study unit 6 keymaking and rekeying - auto locksmith usa · theory of code key cutting reading...

Professional Locksmith

Study Unit 6

Keymaking andRekeying

Congratulations on moving successfully along in your course! You’ve completed fiveinformation-packed units and have added a considerable amount of knowledge toyour locksmithing information base. Be proud of yourself! At this rate, you’ll com-plete your course and move into the professional world of locksmithing in next to notime!

Up to this point, you’ve received important information on keys and key blanks, lockmechanisms, and door and window locks. Now, in this study unit, you’ll learn howto make duplicate keys by hand using simple tools. You’ll also learn how to cut a keywith a key cutting machine, using the special codes available only to professionallocksmiths.

Then, in the next section of this study unit, you’ll explore the rekeying of a lock.(Rekeying is the locksmithing skill that changes the inside of a lock to fit a new key.)Finally, you’ll learn about the keying system used in single and multiple levels ofmaster keying.

After completing this study unit, you’ll be able to

• Identify the tools needed to duplicate various types of keys

• Explain how to properly measure, clamp, and file a duplicate key

• Duplicate a flat key, cylinder key, and bit key by hand

• Describe how to use a key duplication machine

• List the steps to properly cut a key by using key codes

• Rekey a disk tumbler and a pin tumbler lock

• Describe how a master key system operates

• Develop a master key system for a customer’s needs

Preview

iii

DUPLICATING KEYS . . . . . . . . . . . . . . . . . . . . . . . . 1DefinitionDuplicating ToolsKey Duplication StepsOperating a Key Machine

CUTTING KEYS BY CODE . . . . . . . . . . . . . . . . . . . . . 20Theory of Code Key CuttingReading CodesCutting Keys by CodeCode Cutting MachinesCutting Keys on a Code Cutting MachineDecoding Cut Keys

REKEYING DISK/WAFER AND PIN TUMBLER LOCKS . . . . . . . 30Definition of RekeyingRekeying ProceduresToolsRekeying a Basic Disk Tumbler LockRekeying Side Bar Wafer LocksRekeying Pin Tumbler LocksRekeying Various Types of LocksetsRekeying a Rim Cylinder LockRekeying Mortise Locks

MASTER KEY SYSTEMS . . . . . . . . . . . . . . . . . . . . . . 49DefinitionMaster Key System SecurityHow the System WorksDeveloping a Master Key System for a CustomerSelling a Master Key System

THE KEY TO SUCCESS . . . . . . . . . . . . . . . . . . . . . . . 66

KEY POINTS TO REMEMBER . . . . . . . . . . . . . . . . . . . . 66

LOCKING IT UP! ANSWERS . . . . . . . . . . . . . . . . . . . . 69

Contents

v

PRACTICAL EXERCISES EXAMINATION. . . . . . . . . . . . . . 71

PRACTICAL EXERCISE: Duplicating a Key . . . . . . . . . . . . 75

PRACTICAL EXERCISE: Rekeying the Kwikset Door Lock . . . . 79

EXAMINATION . . . . . . . . . . . . . . . . . . . . . . . . . . 91

COMING ATTRACTIONS . . . . . . . . . . . . . . . . . . . . . 95

vi Contents

Do You Know. . .

What does the key code 2, 4, 1, 3, 5, 2 mean?

What is a plug follower?

What is a great great grand master key?

In these pages, you’ll find the answers to these and many more questions dealingwith the subject of keymaking and rekeying today’s most common locks.

DUPLICATING KEYS

DefinitionLet’s begin our study of keymaking and rekeying by describingwhat’s meant by key duplication. Key duplication is the process ofcreating a key that is equal to or better than a lock’s original key.A new key is cut from a key blank (an uncut key) using eitherhand tools or a key cutting machine. If your customer’s key isrelatively new, your duplicate key should be equal in appear-ance and operation to the original. If the customer’s key is oldand worn, your duplicate should look and work as well asthe original key.

Before we discuss specific key duplication methods, let’s takea moment now to look at the tools you’ll need to duplicate akey by hand.

Duplicating Tools

Bench Vises

A small bench vise is useful for many locksmithing tasks. Avise like the one shown in Figure 1 can be clamped onto the

Keymaking and Rekeying

1

edge of yourworkbench or ta-ble. The jaws ofthe vise can holdthe original keyand a blank keyclamped togetherwhile you mark orfile the duplicate.

Many locksmithsrecommend usinga four- to six-inchvise of highquality for keyduplication. Oneway to judge thequality of a vise isto make sure thatthe jaws remain

parallel during opening and closing. The jaws should cometogether perfectly smoothly (Figure 2).

A vise must besecured firmly toyour workbench.If the vise isloosely mounted,it will movearound whenyou file keys andthrow off the ac-curacy of yourkey duplication.

Some locksmithsuse devices calledsoftjaws. Softjawsare shown inFigure 3. Softjawsare purchased

2 Keymaking and Rekeying

FIGURE 1—A qualityvise will help you holdkeys, plugs, and lockshells tightly whileworking on them.

FIGURE 2—The jaws of avise should cometogether perfectlysmoothly.

with the vise orcan be madefrom small piecesof aluminumangle iron. Thepurpose of thesoftjaws is toprevent therough-edged visejaws from de-forming or mark-ing the keys orlock shell beingheld between thejaws.

Marking Pens and Scribes

Additional items you’ll need for key duplication are a simplefelt-tipped marking pen and a scribe (Figure 4). The markingpen is used to color in the blank key. Once the blank is col-ored, the scribe is used to draw lines where the file cuts are totake place. A common sewing needle can be used as a scribe;however, a needle will dull rapidly and require replacement.Therefore, a carbide-tipped scribe of the type used by machin-ists is a better tool. A carbide-tipped scribe will work foryears before requiring replacement.

Files

Metal files are used to cut notches in the metal of the keyblank. These notches must exactly match the notches in thecustomer’s original key. Three types of files commonly usedby locksmiths are shown in Figure 5. These three files are thethree-corner or triangular file, the four-corner or rectangular file,and the round file.

Keymaking and Rekeying 3

FIGURE 3—Softjaws arepieces of aluminumangle iron that will helpprevent damage to theitems placed betweenthe vise’s steel jaws.

FIGURE 4—A carbide-tipped scribe isillustrated here.

Files are available in various grades of quality and with awide range of cutting surfaces, from extremely fine to verycoarse. For most of your locksmith tasks, you’ll use small,fine files. A fine file will remove only a small amount of metalfrom the key blank with each stroke, allowing for greater pre-cision during key duplication.

Files periodically need to have their cutting surfaces cleaned.Since key blanks are made of softer metals such as brass ornickel, metal particles can build up between the file’s cutting

edges. This buildupwill cause a file toslide across, insteadof cut into, a keyblank. A specialtool called a file cardis used to cleanbuilt-up materialfrom files. A file isstroked across a filecard in the oppositedirection from thatused to cut metal.This process isshown in Figure 6.

The following are two important safety tips to rememberwhen using any type of metal file.

1. When using a full-size file, use the wooden or plastic han-dle designed to fit the file. The rear tang of the file can eas-ily injure your hand (usually the palm) if the tang is left


FIGURE 5—These typesof files will be used toturn a blank key into aduplicate key.

FIGURE 6—Files can becleaned by movingthem over a file card.

uncovered. A proper handle will not only prevent injurybut will also make your cutting strokes more accurate.

2. Never use a file as a punch, wedge, prybar, or for anyother purpose except that for which it was intended.Files are made of specially hardened tool steel, and likeglass or other extremely hard materials, a file can shatterif used improperly.

Calipers

One measuring instrument you may find necessary is the ver-nier caliper (Figure 7). A standard caliper can measure objectsplaced between its jaws to an accuracy of one-thousandth ofan inch (0.001 inch). Locksmiths pride themselves on

accuracy, and,when duplicating akey, will attempt tomake a duplicatethat’s an exactmatch of theoriginal.

Calipers are readby placing the keyblank between thejaws of the caliper.

As you can see, you’ll most often be using the larger or out-side dimension-measuring jaws. The second set of jaws isused to measure the inside dimension of a cylinder or otherobject.

The lines on the caliper are then read to give an accuratereading of the thickness of the key blank. The instructionbooklet provided with the calipers will give you detailedinformation on reading dimensions displayed on the caliper.Some special calipers have a dial gage that can be readdirectly while still other expensive calipers use a battery-powered digital readout.

This short list of tools is by no means all of the tools requiredfor key duplication. Tools such as small C-clamps and materialssuch as shim stock will also be used when duplicating certaintypes of keys.


FIGURE 7—Verniercalipers are used inmeasuring key blanks,plugs, pins, and othersuch items.

Key Duplication Steps

Key duplication will require several steps. These steps are

1. Select the proper key blank.

2. Clamp the original key and the key blank together in a vise.

3. Match and mark the areas to be cut.

4. Cut the duplicate key.

5. Inspect the duplicate to be sure it matches the original.

6. Debur (smooth and polish) the duplicate key.

Let’s look at each of these steps in detail now.

Selecting the Key Blank

The first step in duplicating a flat key is to select the properblank key. The blank should have the same blade thicknessand height. If the original key is identified with numbersand/or letters, it is an easy task to go to the key blank booksand locate an exact blank to match the original. If the blank isnot identified, then you will have to go to a key blank boardand select a matching blank. Remember that the shape of thebow does not really matter since it serves no actual purposein opening the lock.

Clamping

After the proper key blank has been selected, the first step infiling a key blank is to secure it in the vise. As mentioned ear-lier, use a set of softjaws on your vise whenever workingwith keys or locks in the vise. These softjaws will prevent therough surfaces of the vise jaws from marking the keys or lockshells. Also, only tighten the vise handle enough to hold theparts securely between the jaws. Excessive pressure will onlydeform the parts.

When holding two keys in a vise for marking or cutting,make sure that all edges are even on the keys as shown inFigure 8. The easiest method of making the key’s edges evenis to hold the bows of the keys together and place the bladesof the keys in the vise. Now, lightly tighten the vise andcheck the surfaces of the keys. If the surfaces are exactly even,


then tighten thevise. If the surfacesare not even,lightly tap themtogether with asoft-faced malletuntil even, andtighten the vise.

When you are plac-ing a single key inthe vise for cutting,the bow and theblade should beheld almost en-tirely between thejaws of the vise.The only area of thekey that should be

seen are the tip of the bow and the area of the blade that is tobe cut. By holding the key in this manner, it will be secureand will not work loose from the vise jaws as you arecutting it.

Marking the Key

The type of marking system that you use depends on what ismost comfortable for you. We’ll examine two methodshere—the smoking method and the marking pen method.

In the smoking method of marking a key (Figure 9), the lock-smith places the blank behind the original key, then clamps the


FIGURE 8—Holding theduplicate and samplekeys even in a vise isvery important duringkey duplication.

FIGURE 9—Here youcan see how aduplicate blank key is“smoked” to placesoot on the key wherethe cuts will be madewith a file.

bows of the keys together in a C-clamp. Then, the keys areheld about one-half inch above a candle flame for about 20seconds. This is termed “smoking” the keys. (Note: Do notoverheat the keys as they can tarnish.)

The soot from the candle flame marks the location of the cutsto be made on the blank key. When the keys are separatedfrom each other, the cut pattern should appear as blackenedareas, as shown in Figure 10. These are the areas to be cutwith the file.

In the marking pensystem, the blankkey is colored us-ing a marking pen.Then, the key blankis placed behindthe original key,and the two keysare clamped to-gether in a vise. Afine- pointed scribeor a sewing needle

is drawn across the cuts in the original key, leaving an “out-line” on the key blank. Then the original key is removed, andthe blank is positioned in the vise for cutting. The blank isfiled until the cuts reach the scribe lines. The cut blank isremoved from the vise periodically and compared to theoriginal key using a caliper. If one or more of the cuts is notdeep enough, the blank is returned to the vise for additionalfiling. Figure 11 illustrates the marking-pen method formarking a key blank.

Some trained locksmiths do not mark the key blank at all.Instead, they will simply place a blank behind the originalkey in a vise and very carefully file the cuts in the blank. Thismethod requires great skill and practice to avoid damagingthe original key with the file while cutting the blank key. Wedon’t recommend that you use this method when you’re firstlearning to duplicate a key by hand.


FIGURE 10—After“smoking” a key,blackened areas willappear where the cutsare to be performed.


FIGURE 11—The marking-pen system for marking a key blank is illustrated here.

Filing

Before you can begin duplicating a key, you must select theappropriate file. For a flat, bit, or barrel key, the best file touse is the rectangular, box, or ward file. This file can producethe square edges necessary for this type of key. For a cylinderkey, a small triangular-shaped file is used.

The natural tendency of a person when filing is to use a rock-ing motion. However, as shown in Figure 12, a file must beused in a straight cutting fashion. In Figure 12a, you can see aside view where the file is held horizontally 90 degrees fromthe blade at all times. In Figure 12b, you see a top view wherethe file is also kept 90 degrees or perpendicular from theblade being cut.


FIGURE 12—Your filingmotion must remainsquare to the key asshown here.

One way to keep your file straight and true is discussed here.

1. Stand in front of your vise and workbench with your leftfoot ahead of your right foot (right handed) or your leftfoot behind your right foot (left handed). This provides astable platform for your upper body movements.

2. Hold the handle of the file in your right hand (righthanded) with your index finger on top of the handle asshown in Figure 13. Left-handed people will hold thehandle with the left hand.

3. Place your free hand at the top of the file holding the tipbetween the index finger and thumb.

When performingthe filing, alwaysmake sure to cutonly on the for-ward stroke. Thecutting teeth on thefile are designedlike the teeth of awood saw. Theycut in one directiononly. If you putpressure on thereturn stroke of thefile, you can dullthe cutting teethand can load up thefile with material.

Two hints from pro-fessional locksmithsare the following:

1. Always start at the bow or shoulder of the key to makethe first cut

2. Always complete one cut before moving on to the nextone.

Filing duplicate key blanks takes a certain amount of practice.It also requires a steady hand and patience. Your first hand-duplicated key may not look or perform as you desire.


FIGURE 13—This is theproper way to hold afile to make clean,square cuts in theblank key.

However, after some practice, your hand-produced key maylook and operate better than the original!

Inspecting the Duplicate

After completely cutting a duplicate, it should be measuredand checked against the sample key. For a flat, bit, or barrelkey, the dimensions of the cuts must be square to each otherand identical in size to those of the sample. The calipers,mentioned earlier, can be used for this measurement task. Fora cylinder key, the depth of each cut should be measuredagainst the sample key.

Deburring

After you complete the cutting, remember to remove all burrs onthe back side of the blade and check your cuts for square corners.

In the next section of the text, we’ll show you how to dupli-cate three popular types of keys: flat keys, bit keys, andcylinder keys. We’ll start with the flat key.

Duplicating a Flat Key

Flat keys fit many types of simple locks such as basic padlocks,drawer locks, and storage boxes. A typical flat key is shown inFigure 14. The two major sections are the bow and the blade.This type of key or key blank is normally made of steel al-though some decorative locks may have a brass alloy flat key.

Place the key blankin your vise withthe sample keybehind it. Align thetwo keys as pre-cisely as possible.Grip as much of thebows and blades aspossible exposingonly the areas ofthe blades to be cut.Remember not to

touch the blank blade as the soot can be easily removed.

Now you are ready to begin cutting the blank. Once your bodyis in the proper position for filing, begin removing the


FIGURE 14—These arethe names of the threemajor parts of a flatkey.

blackened areas of the blank using smooth straight strokes ofthe file. Start at the bow and proceed towards the tip of thekey. Use patience and cut slowly. The idea is to create qualitysquare cuts in the blank the same size as those in the samplewithout removing any material on the sample key.

After all of the blackened areas of the blank are removed,stop filing. Proceeding any further will cause you to cut intothe sample key, ruining both keys. Take the keys from thevise and put the sample key away at this time.

Perform a visual inspection of the duplicate key, looking forsquare, or 90 degree, corners on your cuts. Your cuts shouldappear as shown in Figure 15.

A final inspection can be performed using your calipers tocheck the depth of the cuts. If your duplicate key has notbeen cut deep enough, you can return it to the vise andgradually increase the depth of one or more cuts with yourfile.

Finally, check the height and length of the blade of the dupli-cate key against the sample and file the duplicate as needed.

When you are satisfied that the duplicate key and sample keyare an exact match, remove any burrs on the back of your keywith fine sandpaper or your file.


FIGURE 15—When youhave completed filinga flat key, the cornersof each cut should besquare as shown here.

Duplicating a Bit Key

A bit key and lock are one of the oldest and least secure of alllocking systems. However, many of these systems are still inuse today. Bit keys may also be called barrel keys by somelocksmiths. A typical bit key is shown in Figure 16.

The major parts of abit key are shownin this illustration.They are the bow,post, and the bit orblade. Where othertypes of keys areforged and ma-chined in specialmetal-working ma-chinery, a bit key isgenerally cast in a

mold. This method of manufacture causes the bit key to be ofirregular dimensions due to the shrinkage of the metal in themold.

As with other keys, the first step to duplication is selectingthe proper blank key. Because of the molding process used tomake this key blank, there are certain problems to selecting ablank. Figure 17 shows two keys held end to end. Notice howthe post of the blank is much longer than the post of the origi-nal key in Figure 17a. This extra length would cause the du-plicate key not to work or to bind in the lock. If the bit is ofthe proper dimension, you can simply file the post of theblank until the gap is reduced as shown in Figure 17b.


FIGURE 16—These arethe major parts of atypical bit key.

FIGURE 17—To properlysize a bit key, you mayneed to file the post ofthe key.

The post of the bit key blank can also be too short, as shown inFigure 18a. If this occurs, you can either select another blank orremove a portion of the blade, as shown in Figure 18b. Youmust, however, make sure that reducing the size of the bit willnot shrink it below the size of the bit on the sample key.

There are several different methods of duplicating a bit key.These methods are:

Method 1. The measure and transfer method where each cut ismeasured with a caliper and transferred to the blank for cutting.

Method 2. The shim stock method, where a piece of thin sheetmetal is cut on the sample and transferred to the blank.

Method 3. Purchasing a factory precut key.

In this section, we’ll discuss using the second method, the shimstock transfer method. In using the shim stock transfer method,a small piece of metal stock is wrapped around the bit of thesample key, as shown in Figure 19a. You then take a fine file


FIGURE 18—If the postis too short, you maybe able to file theblade on the blank bitkey.

FIGURE 19—Shown here is the shim stock method of duplicating a bit key.

and remove the shim stock material, as shown in Figure 19b.Be careful not to file on the surfaces of the sample key. Removeonly the shim stock material. Finally, place the shim stockpattern on the blank and file the cuts on the blank as shownin Figure 19c.

Duplicating a Cylinder Key

A cylinder key is one of the most popular keys in use today.A cylinder key and lock system offers a higher degree ofsecurity than either a flat or bit key.

The names for the major parts of a cylinder key are shown inFigure 20. As you can see, they are the bow, shoulder, bladeand tip. Within the blade are the keying groove and the tum-bler cuts.

In duplicating a cylinder key, it is especially important tomatch the blank and sample key. The distance from theshoulder to the tip, the type of blade, and the keyway grooveof the blank must match the sample key. Even the most per-fect cuts on an incorrect blank will not allow the duplicatekey to open the lock.

In this discussion of duplication, we will color the blank keywith a black marking pen instead of “smoking” it under acandle flame. With the key blank colored on one side, placeit behind the sample key in a vise. Once you have both thesample and the original keys properly aligned in your vise,it’s a good idea to C-clamp the bows together. This actionwill allow you to remove and reinsert the keys in the vise forinspection during your cutting.

To cut a cylinder key, you’ll use a small fine-tooth triangularfile. Begin cutting the blank at the center of the first cut closest


FIGURE 20—These arethe names for themajor parts of acylinder key.

to the shoulder of the key. Continue filing this cut until youalmost reach the bottom of the cut in the original key. Theblack marker on the blank key will help you identify thispoint in the cut.

Continue cutting each cut in the key, proceeding from the shoul-der to the tip. If you desire to inspect your progress, loosen thevise and remove the keys by holding the C-clamp. You can thenreinsert the keys in the vise and complete your cuts.

When you havecompleted cuttingthe key, remove itfrom the vise andremove the C-clampto separate the keys.Remove all burrs

from the duplicate and remove all sharp points from the cuts.Sharp points will appear between two similar deep cuts asshown in Figure 21.

Operating a Key Machine

A key machine offers a quick and extremely accurate method ofduplicating most types of keys. For example, flat keys and cylin-der keys can be quickly duplicated on a basic key machine.

A key machine operates much like a basic tracing machine.As shown in Figure 22, the sample key is placed in a vise atthe left of the machine. A thumbscrew is tightened when theshoulder of the key is resting against the vise. The blank keyis then placed in the right vise and aligned with its shoulderagainst the vise. The thumbscrew is then tightened. Beforeturning on the motor of the key machine, the alignment ofthe keys to the guide and cutting wheel is checked and ad-justed as necessary. This action is performed by lifting thevises upwards. Both the sample key in the left vise and theblank key in the right vise should have their shoulders touchthe guide and cutting wheel in exactly the same position. Ad-just the blank key’s position as necessary.

The vises are then lowered and the motor of the key machineis started. Now, slowly lift the left vise containing the samplekey into the guide starting at the first cut to the right side of the


FIGURE 21—Before youcan call a cylinder keyduplicate complete,you should remove allsharp points betweendeep cuts.

shoulder. Now, slide the sample key slowly under the guide.The blank key in its vise will be following this motion of thesample key and will be cut by the specially-shaped cutter.

After one pass of the guide over the sample key, the vises arelowered and the motor stopped. The keys are removed fromthe machine and the duplicate key deburred. Some keymachines have special deburring wheels mounted on theside of the machine for this purpose.


FIGURE 22—Thisillustration shows atypical bench-mountedkey duplicationmachine.


Locking It Up! 1

At the end of each section in your Professional Locksmith texts, you’llbe asked to pause and check your understanding of what you’ve justread by completing a Locking It Up! quiz. Writing the answers to thesequestions will help you review what you’ve studied so far. Please com-plete Locking It Up! 1 now.

1. When you’re duplicating a key, with what type of key do the groovesin the blank have to match those in the sample key?

a. Flat c. Barrel

b. Bit d. Cylinder

2. When filing a duplicate key, what natural tendency should you try toavoid?

_____________________________________________________________________

3. What measuring instrument can be used to measure the blade of akey during duplication?

_____________________________________________________________________

Check your answers with those on page 69.

CUTTING KEYS BY CODE

Theory of Code Key CuttingAs a professional locksmith there will be many times whenyou will be asked to cut a key without ever seeing the originalkey or the lock it fits. For example, a customer may enteryour shop with a padlock for which the keys have been lost.Somewhere on the plug or shell of this lock, a special identi-fier will have been stamped. This number or letter combina-tion means nothing to most people. However, to a locksmithwith the proper code books, this number identifies the codenumbers needed to properly cut a key for this padlock.

Key codes are available for almost every lock made. One ofthe most common types of codes used by locksmiths are thecodes for automobile keys. These codes not only will giveyou the key cutting code but will usually tell you what keyblank to select.

Reading CodesLet’s begin this section by looking at typical key codes for adisk tumbler lock. A short section of a code book listing isshown in Figure 23.

Let’s look at the particular key code for a lock that has thenumber 4021 stamped on its shell. The key cut code for this lockwould be 2, 4, 2, 5, 1. At first glance, this key code would seem

to be a random set ofnumbers. However, eachnumber identifies a cer-tain depth of cut for eachcut on the key blank.These cut depths areidentified in Figure 24.

Notice that each depthdiffers by a dimensionof 0.015 inches, orfifteen-thousandths ofan inch. Also, noticethat the numbers used


Lock Number Key Code

4021 242514022 242424023 252424024 253424025 252414026 241424027 353144028 313524029 314254030 31424

FIGURE 23—Shownhere is a short sectionof a listing in a codebook.

in the key code chart arealways at least two cutnumbers apart. There-fore, key code 24153 isa valid key code whilecode 12345 is not valid.

Now, let’s get back toour sample key code of2, 4, 2, 5, 1. This keywith its cuts plainlymarked is shown inFigure 25.

By reading and using the key codes, you could precisely fileeach cut in the key blank if the spacing of the key cuts wereknown. Spacing will be based on a sample key, or more likely,a spacer, or guide key, as you will see in the next section.

It should be noted that the cut depths given in the chart inFigure 24 will only work for this type of disk tumbler lockkey. In an automotive key, the difference in dimension foreach cut number is 0.025 inch or twenty-five thousandths ofan inch. A typical code book listing and the related cutdepths are given in Figure 26. Notice that the automotive locktable does not follow the same rules as the disk tumbler lockcoding system. In an automotive key, two consecutive keycuts do not have to be separated by at least two digits. In fact,two or more adjacent key cuts can even be the same cutnumber!

Cutting Keys by Code

Although a key can be cut by hand once its codes are known,normally the keys are made using a machine called a code


Code Number Cut Depth

1 0.250

2 0.235

3 0.220

4 0.205

5 0.190

FIGURE 24—A depthchart for a disk tumblerlock is shown here withthe code number onthe left and thedimension from thebottom of the blade tothe bottom of the cuton the right.

FIGURE 25—Here is avisual display of howthe key codes and thecut depths are related.

cutting machine.This machine, whichwill be discussedvery shortly, will usea micrometer feeddevice to set depthand special spacer,or guide, keys. Aspacer key is usedto set the spacingbetween the cuts ona blank. A few sam-ple spacer keys areshown in Figure 27.

Notice that thegrooves on thesekeys are evenlyspaced. If you wereto transfer thesegrooves to a blank,

you would get the spacing required for a functioning key. Allthat would be needed are the proper key codes for the lock tocut a key for a disk, pin tumbler, or other type of lock. Now,

let’s look at how tocut a key using keycodes and a spacerkey on a code cut-ting machine.

CodeCuttingMachines

You learned earlierhow key duplicat-ing machines oper-ate. To review, thesample key isplaced in the leftvise and traced by aguide or stylus as itmoves under the


CODE BOOK LISTING

Lock Number Code

8224 3314248225 3323438226 2523448227 5344438228 5335548229 4454218230 3323558231 1454228232 343523

Cut Depth

1 0.2502 0.2253 0.2004 0.1755 0.150

FIGURE 26—A samplecode book listing andcut code depths forthe code numbers isgiven here.

FIGURE 27—These arespacer, or guide, keysyou would use on acode cutting machineto ensure properspacing of the cuts.

stylus. The blank key is placed in the right hand vise whichfollows the motion of the left hand vise containing the sam-ple key. The blank key is cut by a specially shaped wheel onthe right hand side of the key duplicating machine.

A code key cutting machine will normally look like a back-wards key duplication machine. The blank key is held in theleft hand vise while the spacer, or guide key is in the righthand vise.

Many code key cutting machines also have a micrometer,which is basically an extremely precise screw and nut assem-bly. It operates in the same fashion as a bolt and nut. How-ever, the micrometer’s threads are so fine that one revolution ofthe barrel may move the center shaft only ten-thousandths(0.010) of an inch. A calibrated scale on the micrometer is usedto set the depths of the cuts on the code machine. A V-shapedblock at the end of the micrometer’s screw is used to track thegrooves in the spacer key. It should be noted that the distancebetween the blade bottom and the bottom of the groove on aspacer key is 0.025 inch. This, as you may remember, is thethickness of a blank key’s blade and is equal to a number onecut on the keys you have seen previously.

Cutting Keys on a Code Cutting MachineCutting code keys by machine is actually very simple as longas you set up the machine properly. The steps to propersetup are

Step 1. Make sure a V-type cutting wheel is in place on themotor-driven arbor.

Step 2. Check the installation and tightness of the V-shapedguide on the end of the micrometer.

Step 3. Set the micrometer to zero by turning it in a clockwisedirection. Never force the barrel when turning the mi-crometer—its fine threads could be damaged.

Step 4. Carefully mount your spacer key in the right-handvise. It must be mounted square to the machine. If necessary,place a piece of shim behind the blade of the key to hold itsquare in the vise.

Step 5. Loosely mount the blank key in the left-hand vise.


Step 6. Lift up on the right-hand vise that holds your spacerkey.

Step 7. Align the shoulder of your spacer key to the V-guideat the end of the micrometer.

Step 8. Align the shoulder of the blank key in the left-handvise with the cutting wheel.

Step 9. Tighten the vise and recheck your alignment of bothkeys by lowering and raising the vises. Both shoulders ofboth keys should be centered on the V-guide and V-cutter atthe same points on the shoulders of the keys.

Now let’s see how to cut a key by codes on a key machine. Asan example key, let’s use an automotive key with the code8229 stamped on the side shell of the lock. Going into ourcode book, we can see that the number 8229 would give us akey with cut codes of 4, 4, 5, 4, 2, 1.

Placing these numbers vertically from the shoulder cut at thetop to the tip cut at the bottom gives us

445421

Installing the cut dimensions next to the vertical column ofcut numbers would give us

4 0.1754 0.1755 0.1504 0.1752 0.2251 0.250

Let’s add a third column to our key code chart. This columnwill be the difference in inches between the cut code valueand the no cut or number one cut of 0.250. For example, cutnumber 5 has a dimension of 0.150. Therefore, subtractingthis value from the number 1 or no cut value of 0.250 gives us0.100 inches. Creating this third column will give you a chartthat appears on the following page.


The differencecolumn, the thirdcolumn of ourchart, shows thedimensions wewill dial on themicrometer toperform the cuts.Before turning onthe motor of thecode key machine,

doublecheck that the cutting wheel is tight, the keys arefirmly held in their vises and the micrometer V-guide issecure. Next, you can set the first value for code cut 4, or0.075 inch. Do this by turning the knob of the micrometercounterclockwise until it has retracted the V-guide 0.075 inch.Your manual for your code key machine will give you de-tailed instruction on the reading of the micrometer’s scales.

Now you can turn on the code key machine and slowly raisethe right hand vise containing the spacer key upwards to-wards the V-guide. Our first cut will be performed on thenotch on the spacer key nearest the shoulder of the key. Sincethis cut is rather deep, a large amount of material will beremoved from the blank. Proceed slowly forward with theright-side vise until the guide on the micrometer is fullyseated in the first notch or groove in the spacer key. Once theV-guide has bottomed in the groove, retract the vises.

Your next cut in the blank will also be a number four cut. Itwill be of the same dimension as your first cut. Therefore, it isa simple process of raising the right-hand vise until the secondgroove in the spacer key is fully seated in the V-guide of themicrometer.

The third cut is a number five cut with a dimension of 0.150inch. The difference from cut number 1 is 0.100 inch. Thismeans that you can increase the reading on the micrometerby turning the micrometer an additional 0.025 inch in thecounterclockwise direction. If this seems confusing, you cansimply re-zero the micrometer by turning it clockwise to zeroand then turn it counterclockwise to 0.100 inches. When themicrometer is properly set, raise the right hand vise until theV-guide rests in the third groove of the spacer key.

Your fourth cut is a number four cut that is similar to the firsttwo cuts you performed. Reset the dial of the micrometer to


Code Cut Depth DifferenceNumber from Cut 1

4 0.175 0.0754 0.175 0.0755 0.150 0.1004 0.175 0.0752 0.225 0.0251 0.250 0.000

0.075 inches by either turning the micrometer clockwise 0.025inches or return the micrometer to zero and back out 0.075inches. Again raise the right-hand vise until the fourthgroove in the spacer key is fully seated in the V-guide.

The fifth cut can then be performed in the blank. This fifth cutis a number two cut which at 0.025 inches is a rather shallowcut. Set this reading on the micrometer and raise the right-hand vise until the fifth groove of the spacer key is fullyseated in the V-guide.

The sixth cut in your blank is really no cut at all. The dimen-sion is 0.250 which is the actual dimension of the blade of theblank key. Therefore, its time to turn off the motor and waitfor the cutter to stop turning. Now, remove the cut blank key,debur it, and inspect the cuts. The final key should appear asshown in Figure 28.

As you can see, if you have the lock number or key numberin some cases, you can duplicate a key without looking at anoriginal key or the actual lock. Using a spacer key and yourmicrometer V-guide adjustment, almost any type of key canbe created.

Here are a few safety tips to use when working with a codecutting machine:

1. Always be sure to completely read the manual for yourmachine before using it.

2. Wear safety glasses with side shields. Small particles ofbrass, nickel, or bronze will be thrown from the machinewhen you are grinding the key blank. These particles arenon-magnetic and very difficult to remove from youreye. Plus, the particles can be very sharp and cause sig-nificant eye damage.


FIGURE 28—This is howa sample code cut keywould appear.

3. Avoid wearing loose fitting clothing, ties, and jewelry.These items can get caught in between the grindingwheel and the blank and pull you towards the machine.

4. Always keep the floor and workbench area around thekey cutting machine clean and clear of obstructions.

Decoding Cut KeysDecoding a previously cut key is actually a very simple task.The key will probably have a number or letter on it. Usingthis number, you may be able to go directly to your codebook and get the key cut codes for that particular key. Whatcould be easier? However, if these numbers are missing, youmay still find a blank identifier number or letter somewhereon the key. Then you will have to measure the key to derivethe key cut codes.

Measuring a key for cut codes is a simple matter of using yourvernier calipers to measure each cut as shown in Figure 29.

Let’s say, for exam-ple, that a customerbrings you a wornignition key thatwill not alwaysoperate the auto-mobile. Since thekey is worn, you donot want to simplyplace it in a dupli-cation machine.

To cut this key using codes, you will have to measure eachcut and create the codes for yourself if no identifying num-bers exist on the key.

Begin the process by clamping the bow of this key to the bowof your spacer key. You will, of course, have to select theproper spacer key to match the manufacturer’s. Using aneedle or scribe, mark the sample key at each point a grooveoccurs on the spacer key. A very fine mark is all that isneeded. Separate the keys and, using your calipers, start atthe point nearest the shoulder of the key and measure eachcut in order.


FIGURE 29—To decodea precut or samplekey, measure each ofthe cuts in the key witha vernier caliper.

Shown here is a sample ofthe measurements youmight make.

As you can see, none ofthese numbers matchesthe dimensions for a newcode key since this key isworn. We will have to in-crease the measurement to

the next largest size to properly get the codes. You shouldnever decrease the sizes since key wear has removed materialfrom the key, reducing the cut sizes.

Shown here are the cut numbers, measured size, and in-creased size along with the key code number for that cut.

Thus, the proper key code for this key would be 4, 1, 2, 3, 3, 5.By using your spacer key and these numbers, you couldquickly create a working key for your customer’s vehicle. Aspreviously mentioned, you’ll find that a large amount of yourkey code cutting work will be in the area of automotive keys.As you will soon see, your other code cutting work will bemade up of cutting keys for rekeyed locks and for masterkeying systems.


Cut Measurement Increased Code NumberValue

1 0.160 0.175 42 0.235 0.250 13 0.215 0.225 24 0.190 0.200 35 0.191 0.200 36 0.135 0.150 5

Cut Measurement

1 0.1602 0.2353 0.2154 0.1905 0.1916 0.135


Locking It Up! 2

1. How many cuts does a typical automotive key have?

______________________________________________________________________

______________________________________________________________________

2. What is the purpose of a spacer, or guide, key?

______________________________________________________________________

______________________________________________________________________

3. If you are decoding the cuts on a worn automotive key and you read adimension of 0.167, what would be the proper code number and di-mension for the cut?

______________________________________________________________________

______________________________________________________________________

4. When cutting a key on a code machine, which cut should you begin at?

______________________________________________________________________

______________________________________________________________________


REKEYING DISK/WAFER AND PIN TUMBLER LOCKS

Definition of Rekeying

If you are asked by a customer to rekey a lock, it means thatyou will disassemble the lock and either replace or realignthe disks/wafers or pins. When you have completed this op-eration, the original key will not operate the lock. An entirelynew key will need to be cut to open this lock.

Rekeying is often performed when your customer purchasesa home, car, or other object for which the original owner mayhave retained a set of keys. This is especially true when thecustomer considers the rekeying of the locks as less expensivethan the purchase of new locks. Also, your customer mayconsider that the locks presently in place are appealing andhave no desire to change them.

Rekeying Procedures

Rekeying a lock will require you to perform the following gen-eral steps. (We’ll give you more detailed instructions on rekey-ing disk/wafer and pin tumbler locks later in this section.)

Step 1. Remove the plug according to the manufacturer’s in-structions for the lock you’re working on.

Step 2. Place the plug in your vise.

Step 3. Remove each disk or pin from the plug, and placethem in a tray in the order in which you remove them.

Step 4. Change the order of the disks or pins and replacethem in the plug.

Step 5. Cut a key to match the new arrangement of disks orpins.

Step 6. Reinsert the plug into the shell.

Step 7. Test the new key to make sure it works.


ToolsThe tools you will need to rekey a lock are very similar to thoseused in cutting a key blank. You will need files, calipers, and avise for holding the shell and plug. In addition, a few newtools may be necessary to help you rekey a lock efficiently.

An electric drill and small drill bits may be needed to drillinto the shell or plug of the lock to remove the plug retainer.

A small, quality electric drill will suffice. The manufacturer’sdata sheets will show you exactly where to drill to spring orremove the plug retainer. A pair of fine tweezers will be help-ful to remove the disks or pins when rekeying a lock. Somelocksmiths, in fact, will have multiple pairs of tweezers, somewith the ends bent at a 45 degree, or a 22 1

2 degree angle.

A pin tray is also a useful aid when rekeying a lock. A pintray has multiple dividers, as shown in Figure 30. As youremove each disk, or lower pin, place it in its own specialsection of the pin tray. As the next disk or pin is removed,place it in the next separated compartment. This will keep thedisks or pins in order as you work on the lock.

Some locksmithswill also mount ashallow drawerbeneath their viseon their workbench.This drawer isopened when theyare removing a

plug from a lock’s shell. The drawer will then catch any loosesprings, disks, or pins that may fall from the plug, eliminat-ing the all-too-often futile search around the floor.

A special follower plug or dowel will be necessary to removethe plug of a pin tumbler lock. This follower plug or dowel isused to prevent the upper pins and springs from exiting theshell when the plug is removed. More will be seen on this itemwhen we cover the removal of the plug later in this section.

A straight, pointed tool such as a lock pick or a thin carpenter’sawl may be needed on some locks to release the retainingspring after a hole is drilled in the shell. Also, various typesof screwdrivers, slotted and Phillips, may be necessary to


FIGURE 30—A pin traywill help you keeppins, disks, and springsin order as you removethem from the plug.

remove plug-retaining screws on some types of padlocks,and on mortise-type locks.

Rekeying a Basic Disk Tumbler Lock

In its most basic form, a disk tumbler lock is used for lockingcabinets, trunks, and on some low security padlocks. Moreexpensive disk tumbler locks can be found on higher-pricedpadlocks and on automobiles.

In review, a disk tumbler lock holds the plug in place withone or more disks that fit into a slot in the shell of the lock.The disks are spring loaded and held in the slot. When theproper key is inserted into the lock, the disks are centered inthe plug away from the slot or slots in the shell, allowing theplug to turn. The disks within the plug are slotted for keyentry. The slots are positioned in different places on thedisks, thereby requiring a key with different cuts along itsblade to open the lock. These different disks with theirstaggered slots allow us to change the keying system for thelock.

To begin rekeying a disk tumbler, the first step is to removethe plug from the shell. In the lock shown in Figure 31, a holehas been drilled in the shell to allow access to the retainingclip that holds the plug in place. On some disk tumbler locks,this hole may be present.


FIGURE 31—Here aretwo locations where ahole must be drilled toremove the plug of adisk tumbler lock.

In Figure 31(a), a small hole has been drilled in the shell nearthe top centerline of the plug. A typical padlock example isshown in Figure 31(b). Here, a hole has been drilled foraccess to the retainer. These holes can later be filled withan epoxy or other material and sanded, then polished to dis-guise their location.

A small object such as a lock pick, thin awl, or other suchobject can then be placed into this drilled hole. By applyingpressure, the retaining ring for the plug can be collapsed.With the key located in the plug, turn the plug slowly whilepulling outward. The plug should slide from the shell.

Once the plug is removed, you can place the plug in yourvise and begin removing the disks. As each disk is removedfrom the lock, place it in order in a pin tray or other smallcontainer. When all of the disks have been removed, set thepin tray aside and clean the plug.

The plug should be cleaned in a safe and non-flammable sol-vent. Do not use gasoline or kerosene. Spray solvents andother types of cleaning solutions are available from locksmithsupply houses. If you desire, you can also use electrical spraycleaners such as those used on volume controls and otherelectronic components.

Now you can begin reloading the disks into the plug. Remem-ber that you want to stagger the disks in the plug to rekey it.The disks that you have in the plug tray, or container, shouldlook like those shown in Figure 32.

Note that there arefive different sizesof disks shown. Notall five may appearin a disk tumblerlock that you open.Instead, one ormore disks may berepeated within the

lock. You may notice that the disks can have a numberstamped on them. This number identifies the type of diskyou’re working with.

You must switch at least two of the five disks in the lock toproperly rekey it. Often three disks, such as the first, third,and fifth disks will be swapped in position in the tumbler to


FIGURE 32—The fivedifferent sizes of disksin a disk tumbler lockare shown here.

properly rekey it. The disks, of course, must be of a differentnumber or slot height. If the first and third disks are bothnumber three disks, swapping them would provide no rekey-ing action.

Now with the disks swapped, it’s time to rekey the lock.Locksmiths may use different methods to cut a key for thisplug. Some of the methods that may be used are

Method 1. Code cutting the key. This is a relatively easy tasksince you know exactly what disk is in what position withinthe plug.

Method 2. Cut the areas of the key by hand where the diskshave not been moved using the original key as a guide. Nextcut the areas where the disks have been moved by measuringthe original cuts in the key. Swap the location of these cuts onthe blank and file these cuts in the new key.

Method 3. A third method of cutting a key would be to usethe original key to mark the spacing of the cuts. Oncemarked, the key is inserted into the plug and the heights ofthe disks are noted. The key is removed from the cylinderand cuts are continued where the disks extend from the plug.Here you should go slowly. Reinsert the key and recheckdisk height many times. You can always remove morematerial from the blank but you can never add material.Never file the disk. When you are done filing, all of the disksshould be even with the plug with the new key firmly seatedin the plug.

Rekeying Side Bar Wafer LocksA side bar wafer lock is constructed much like a disk tumblerlock seen previously. However, the lock does not dependupon the disks to disengage from a slot in the shell. A sidebar wafer lock uses the wafers, which resemble disks, to re-lease a side bar that disengages from a slot in the shell. Oncethe side bar is released, the plug can turn, opening the lock.The side bar is only released when all five or six wafers ordisks are in the proper position as set by the cuts in the key.A typical wafer/side bar arrangement is shown in Figure 33.

Side bar wafer locks provide a greater degree of security thansimple disk tumbler locks. They are extremely difficult topick and can be made inexpensively and in a compact


package. Side barwafer locks willmake up a largeamount of yourlocksmith work.This is because theyfind use as ignition,door, and trunk orrear hatch locks formost General Mo-tors automobilesand light trucks.

The five types ofwafers that youmight find inside aside bar wafer lock

are shown in Figure 34. These wafers may be identified by anumber, one through five, stamped on the wafer. However,on some wafers, you may see the letters C, N, B, or Y. Theseletters stand for copper, nickel, black and yellow, respec-tively. If the lock you disassemble has no letter marking onone wafer, it will be equal to a number five wafer.

The removal of the lock from the vehicle is the first step inrekeying this lock. Ignition and trunk locks are normally re-moved by driving out a retaining pin to release the shell ofthe lock. Door locks are removed after removing the lockinglinkage. Normally a specially shaped clip is used to hold the


FIGURE 33—In thiscutaway view of a sidebar wafer lock, youcan see how the disksor wafers must bealigned to have theside bar come free ofthe shell.

FIGURE 34—These are the five sizes and the size identifiers for a side bar wafer lock.

lock shell. Exact details on lock removal from automobilesare available in automotive service manuals.

To rekey this type of lock, you will have to remove the springand disk retainer cover. Pry upwards on the cover with a smallscrewdriver and it will come free of the shell. Very often, thiscover will be bent or distorted upon removal and require re-placement after you have moved the disks. These covers areavailable at locksmith supply stores or by mail order.

With the cover removed, begin lifting the six internal springsfrom the lock with a pair of tweezers. Place these springs inyour pin tray or other container.

The most important step in rekeying this lock comes next.You should decode the original key or study the wafers in thelock carefully to decide exactly which disks to move. If theoriginal key code was, for example, 4, 4, 5, 3, 4, 1, thenswitching the first and second, or first, second, and fifth wa-fers would not rekey the lock. A better rekeying methodwould produce a new code key arrangement such as 4, 5, 4, 4,1, 3. This arrangement would surely render the original keyuseless.

The actual rekeying will be performed by lifting the desig-nated wafers out of the plug and replacing them in their newlocation. After this action has been performed, you can cleanthe lock thoroughly and begin replacing the springs. Oncethe springs are replaced, a new spring retainer cover can beinserted in the shell. Make sure this retainer is held in theshell tightly. If it is loose, bend the tangs of the retainerslightly outward to hold it in the shell. You can also lightlydent the tangs with a punch or other sharply pointed objectto further improve the retaining force of the tangs.

Finally, you are ready to cut the key for the lock. The easiestmethod is to record what wafers are in position in the lockand code cut a key. The chart on the next page lists the codenumbers, cut dimensions, and micrometer settings for yourrekeyed side bar wafer lock.


Now you can cut the new key for the lock using the micrometersettings listed in the chart above. Remember to debur this keyand check its operation before giving the key to your customer.It is also a good idea to lightly lubricate the lock using WD-40.Never use oil, grease, or any type of mineral- or paraffin-baselubricants. These types of lubricants tend to collect dust and dirtover time. This dust and dirt will later become a thick paste. Thispaste will cause the lock to malfunction. WD-40 comes in a canwith a small nozzle and cap. This nozzle can be inserted into thelock and the tube squeezed to place a small amount of WD-40 inthe moving mechanisms of the lock.

Rekeying Pin Tumbler Locks

Let’s begin this section with a review of how a pin tumblerlock operates. This type of lock is one of the most popular inuse today for home entry locks, padlocks, and other types ofmedium security locking devices.

The plug of this type of lock is held from rotating by theupper pins. The upper pins are all of the same height in mostpin tumbler locks while the lower pins are of differentheights.

To open this lock, the key pushes upward on the lower pinsas shown in Figure 35. When all pins are properly raisedeven with the top of the plug, the plug can be rotated releas-ing the locking mechanism. One term you will encounteroften with pin tumbler locks is shearline. The shearline is thepoint at the top of the plug that the lower pins must reach inorder to turn the plug. If an improper key is used, the lowerpins may be raised too far above the shearline, inhibiting theturning of the plug. An improper key may also not raise the


Code Cut Depth MicrometerNumber Setting

4 0.175 0.0755 0.150 0.1004 0.175 0.0754 0.175 0.0751 0.250 0.0003 0.200 0.050

lower pins to the shearline. This action would allow theupper pins, under spring pressure, to remain below theshearline, also inhibiting the turning of the plug.

The object of rekeying a pin tumbler lock is to gain access tothe lower pins and alter their position in the lock. This pro-cess will cause the original key to become inoperative.

Gaining Access to the Lower Pins

There are two basic methods of gaining access to the lowerpins. These methods are

Method 1. Removal of the spring retainer on some types oflocks.

Method 2. Removing the plug assembly on most pin tumblerlocks.

Some door locks have a spring retainer similar to the oneseen earlier on a side bar wafer lock. If this retainer is re-moved, the springs can be removed and placed in your pintray. Next, you can block all but one hole in the shell anddump out the upper and lower pin, placing these pins inyour tray. Continue this operation until all pins are removedfrom the lock. Now clean the lock using a safe spray solventor by dipping the plug and shell into a cleaning tank. Oncedry, reassemble the lock by placing the lower pins into theholes in a different order from which they were removed. It isa good idea to record on a piece of paper which lower pinswere switched. Then, when you cut the key for this lock, youcan measure the original key and switch cut depths on theblank key.


FIGURE 35—When theproper key is insertedinto the plug, the lowerpins are raised to theshearline, allowing theplug to turn.

With the lower pins in the lock, simply replace the upperpins, springs, and spring retainer. If the spring retainer wasdamaged during removal, replace it with a new retainer.

To cut a key for this lock, duplicate the cuts in its original keywhere the pins were not swapped. Next, using your calipers,measure the cuts in the sample key where the pins wereoriginally located and perform these cuts in the new key inthe new pin locations. Go slowly and check your work byinserting and checking key operation after you think you areclose to the final cut distance. Lubricate the lock with WD-40and return the shell to its locking mechanism.

The second method of rekeying a pin tumbler lock is muchmore time-consuming and detailed. Unfortunately it is themore common method since many locks do not have springreturner plates or covers.

In this second method, you must remove the plug from theshell. Let’s begin by looking at a lock where the plug is re-moved by removing a retainer plate. Such a lock is shownin Figure 36. This type of plug retainer is held by two smallmachine screws on the retainer plate.

Once the retainer isremoved, youcould simply insertthe key into theplug, turn the plugwith the key, andpull the plug fromthe shell. However,all of the upperpins and springswould then popfree of the lock. Al-though these pinsand springs can beeasily replaced

with a tweezers, reinserting the plug would be difficult as theupper pins would try to block the insertion of the plug. Forthis reason, it is suggested that you use a plug follower. Thisfollower will hold the upper pins and springs in the shellwhile you work on the lower pins and the plug. The use ofthe plug follower is shown in Figure 37(a) while some typesof plug followers are shown in Figure 37(b). You may note


FIGURE 36—In this typeof pin tumbler lock, theplug can be removedafter two screws areunscrewed from theshell, releasing theretainer plate.

that the plug followers shown have different ends to matchthe type of plug you are working on.

To use a plug follower properly, you remove the plug re-tainer, insert the key into the plug, and turn the plug about45 degrees. Next, insert the proper follower into the plug andgently push forward allowing the plug to exit the shell. Withthe plug follower in place, you can completely remove theplug while retaining the upper pins and springs in the shell.

With the plug out of the shell, the lower pins can now be re-moved from the plug and placed in the pin tray. To rekey thislock, you can then simply shift the positions of the lower pinsin the plug. After the pin locations are shifted in the plug, youmust make a new key to fit the new lower pin arrangement.


FIGURE 37—To properlyremove the plug,place the correctlyshaped plug followeragainst the plug andpush the plug from theshell.

This key cutting process is best undertaken now, with theplug out of the shell of the lock.

In cutting a newkey, first insert theproper blank in theplug as shown inFigure 38. As youcan see, the lowerpins are raised

different amounts above the shearline. The object of the keycutting will be to cut slots in the blank that will allow thelower pins to drop even with the shearline.

To mark the blank key, remove the lower pins, keeping themin proper order. Insert a pencil or carbide scribe in each holeof the plug and make a mark on the blank. Now, remove theblank, reinsert the lower pins in the lock and begin filing theblank key at the first cut mark nearest the shoulder of thekey. Every so often, insert the blank into the plug and checkthe height of the first pin. If it is above the shearline, keep fil-ing until this pin is even or just slightly above the shearline.Continue filing the blank until all pins are even or just abovethe shearline.

With the pins just above the shearline, you have two choicesin completing the key. You can

1. Carefully continue filing on each cut of the blank keyuntil the pins are even with the shearline.

2. File the lower pins until they are even with the shearline.This method of leveling the lower pins is suggestedsince it is more accurate and much easier than perform-ing fine cuts in the blank.

After the pins are filed to the shearline, the plug can bereinserted into the shell. You must first mate the plug to thefollower dowel to eliminate a gap between the dowel and theplug. Any gap will allow the upper pins and springs to be re-leased from the shell. Once mated, simply push the plug intothe shell until it bottoms in the shell. Now, replace the retainerand its screws and then check the operation of the key. Cleanthe lock thoroughly and lubricate it. Finally return the shell tothe locking mechanism and retry the key in the mechanism.


FIGURE 38—With theblank in the plug, thedifference in height ofthe lower pins can beclearly seen.

Rekeying Various Types of LocksetsIn this section, we will look at how to rekey specific types oflocking mechanisms. We will begin by looking at key-in-knob locksets followed by dead bolts and then rim andmortise cylinder pin tumbler locks.

Two typical key-in-knob locksets are shown in Figure 39. Thelockset shown in (a) has no deadlocking pin and is, therefore,a minimum security lockset. The locked door can be openedrather easily—placing a credit card or other stiff piece ofplastic between the doorjamb and the latch will open it. Thelockset in (b) has a deadlocking pin that presses against thestrike plate, preventing such a simple opening of the door.

The first step in rekeying a key-in-knob lockset is to gainaccess to the shell and plug, or cylinder assembly. To gainaccess, you must remove the inner knob and rose. In order toremove these items, refer to the manufacturer’s data sheetsfor the lock. Some locks have simple removal procedures forthe inside knob. For example, all you need to do is to pressinward on a retaining clip and wiggle the knob free. The rosecan then be twisted and pulled to remove it. Other manufac-turers use special tools to remove the knob. One such tool isspecially designed with a spanner wrench on one side and aknob removal tool on the opposite side. Such a tool is shownin Figure 40.


FIGURE 39—Here aretwo types of latches ona typical key-in-knoblockset.

FIGURE 40—A spannerwrench, such as theone shown here, canbe used to tightenretainers and removeinterior knobs.

Once the inside knob and rose trim piece are removed, two ormore screws will be visible. These screws can then be removedto release the internal assembly of the lockset. This assembly isshown in Figure 41.

The cylinder assembly can be clearly seen to the left side ofthis illustration. This cylinder assembly must be separatedfrom the outside knob after it’s pulled from the outside hous-ing. In this model of lockset, a small steel pin is depressed atthe rear of the cylinder. Then, a retaining ring is unscrewedand the cylinder freed of the exterior knob.

To remove the plug of this lock, you must use a speciallyformed plug follower. Insert the key into the lock and turn itabout 45 degrees. Insert the follower into the back of the plugand push the plug gently forward. The follower will retainthe upper pins and springs in the cylinder.

Most key-in-knob manufacturers make a special rekeying kit.This kit contains new lower pins and a precut key. The rekeying


FIGURE 41—This is the internal assembly of a typical key-in-knob lockset.

of this lock is fairly simple. Place the precut key in the plugand insert the new lower pins in the plug. The proper combi-nation of lower pins will leave all pins at the shearline of theplug. If any pins are slightly higher than the shearline, simplyfile them level with the plug.

Reassembly of this lock is basically the reverse process ofdisassembly. Place the plug against the plug follower andpress forward until the plug is fully seated in the cylinder.Next, screw in the rear plug retainer and replace the steel pin,if present. Replace the cylinder in the outside knob and reas-semble the internal assembly of the lockset into the door.Tighten the retaining screws next and replace the rose andinside knob. Most inside knobs will simply press in until theyare retained by a keeper.

As mentioned, you should obtain the manufacturer’s datasheets for the types of locks you will be working on. Thesedata sheets will save you significant time in disassembly andrekeying. For example, some key-in-knob lockset manufac-turers do not use a retainer to hold the cylinder in the outsideknob. Instead, once the knob is removed from the lockset, allyou need to do is hold the knob in your hand and rotate thekey clockwise 180 degrees. Now pull back on the key to pullthe cylinder out of the knob. Without the manufacturer’s in-formation, you could spend considerable time searching forthe retainers and removing the inside knob assembly.

Two variations to the standard key-in-knob lockset are thedeadlocking lockset and the dead bolt. As shown in theprevious figure, the deadlocking spring latch mechanism issimply a variation of the simple spring latch mechanism. Theupper latch unit is deadlocking while the lower unit is a sim-ple spring latch assembly. Rekeying a deadlocking or a deadbolt assembly follows the same principles seen earlier.

Rekeying a Rim Cylinder LockRim cylinder locks are often used on entrance doors such as cel-lar and garage side-entrance doors. This type of locking mecha-nism is extremely easy to install and offers medium security.

A rim cylinder lock consists of three basic parts. These threeparts are the rim cylinder, rim latch, and strike box. To installthis type of lock, a circular hole is bored in the door using a


template. This hole accepts the rim cylinder. The cylinder hasan outside circular-shaped security plate and an internalcylinder-holding plate. This internal plate is larger in dia-meter than the bored hole and securely holds the cylinder in

place in the hole.The rim latch as-sembly is held tothe door by three ormore screws. Therim latch is placedover the drive barthat exits the rear ofthe cylinder andthen securelyscrewed into thedoor. The strike boxis then positionedon the jamb overthe extended latchand also secured to

the doorjamb by means of screws. This assembly is shown inFigure 42.

To rekey this type of lock, you must first remove the rim latchassembly from the door. Then, the cylinder retaining plate andscrews will be visible. The next step is to remove the two cylin-der retaining screws and press the cylinder and exterior secu-rity plate through the outside of the door. You now will havethe cylinder assembly with the tailpiece exposed for rekeying.

Most rim cylinder locks can be rekeyed using one of the twopreviously mentioned methods. You can either remove thespring plate retainer and change pins or push the plug fromthe lock and change the location of the lower pins. In thissection, we will discuss pushing the plug from the cylinder,since spring retainer plate removal can often damage thecylinder or shell.

To remove the plug of the lock, you must first remove thetailpiece. On most rim cylinder locks, the tailpiece is held tothe plug by means of a hollow pin, or roll pin. This pin servestwo purposes. First it holds the tailpiece to the plug, and sec-ond, it retains the plug in the cylinder. You can push the pinfrom the lock by using a small tool called a pin punch and asmall hammer.


FIGURE 42—A rim latchlocking system is easyto install and offersmedium security.

Whenever using a pin punch and hammer, be sure to wearsafety glasses. In using a pin punch, simply hold it verticallyon the pin and gently tap it with a small hammer. It is betterto tap it several times rather than drive the pin free forciblywith a blow of the hammer. When the pin comes free of theplug, remove the tailpiece. Now, using pressure against theface side of the plug, place a follower against the plug andpush the plug free of the cylinder.

The rest of the rekeying operation follows the proceduresgiven earlier. Simply swap the locations of different-sizedlower pins and cut a new key for the lock. Remember tocheck the new key in the plug and to clean the cylinder be-fore reassembly.

Reassembly of the rim cylinder lock is basically the reverse ofdisassembly. Place the plug back into the cylinder and, usingthe pin punch, replace the pin through the plug and tailpiece.Insert the cylinder into the security ring and replace it in thehole in the door. Next, replace the cylinder retaining plateand its two screws that thread into the cylinder. Tighten thesescrews firmly, but not so firmly as to strip the threads in thebrass-alloy cylinder. Finally, replace the rim latch assemblyby meshing the tailpiece into the interior thumbturn and re-place the three screws into the door. Lubricate the lock andcheck its operation to complete the rekeying.

Rekeying Mortise LocksMortise locks are available in many types and styles. Somesmall mortise locks are used for cabinet doors in mostly lowsecurity applications. Mortise door locks are available in awide range of styles from low- to high-security levels.

This type of locking mechanism fits into a special pocket ormortise that is milled into metal doors or otherwise routed orcut into wooden doors. A strike plate mounted in the jamb orin a second mating door accepts the mortise lock bolt that isactuated by the keyed cylinder.

To remove the cylinder of a mortise lock, a set screw must beloosened. This cylinder-retaining set screw is hidden behinda hole in the face plate of the lock. A special tool called an Allenwrench is most commonly used to remove this set screw. An Al-len wrench is a six-sided wrench that fits into the recess in the


head of the Allen screw. However, some mortise locks mayhave a slotted or Phillips head screw that can be loosened us-ing a thin blade screwdriver.

Once the set screw is loosened or removed, the cylinder is sim-ply unscrewed from the lock assembly. In some cases, you willhave to press in on the latch assembly to free the drive cam atthe rear of the cylinder. As with the previous locks mentioned,it is often a better idea to remove the plug of the cylinder to re-key this lock. The steps to plug removal are

Step 1. Remove the two-slotted or Phillips head screws at therear of the plug to remove the drive cam and plug retainerplate.

Step 2. Using a plug follower that matches the plug, pressthe plug from the cylinder.

Step 3. Change the location of the lower pins in the plug.

Step 4. Reassemble the plug in the cylinder and check yournew key’s operation.

Step 5. Reassemble the cylinder into the mortise lock, lubri-cate the lock and check its operation.

This section of this study unit described the rekeying of vari-ous types of disk/wafer and pin tumbler locks. It is assumedthat your customer had the original keys for the lock andwanted the lock’s “combination” changed. But what if thecustomer lost the keys to the lock? The next study unit willshow you how to open locks without keys. Once you openthe lock, you could then create a key by the various methodswhich you have seen here.



Locking It Up! 3

1. Why must you drill a hole in some types of locks before you canrekey them?

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2. If a wafer in a side bar lock is stamped with the letter “C,” whatdoes this mean?

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3. In rekeying a pin tumbler lock, should you file the upper pins?

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4. How can you remove the cylinder from a mortise lock?

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MASTER KEY SYSTEMS

Definition

A master key system is a system where individual keys willopen a certain lock and a special key will open all the lockswithin a system. Hotels, motels, apartment buildings, univer-sities and other such large establishments often will use amaster key system. This system allows individual access tocertain rooms or areas using specific keys and total access toall areas by security personnel using master keys.

Let’s begin looking at master key systems by studying someof the terms used in master keying.

Change Key. This is a key that will open only one specificlock within the master key system.

Bitting. Bitting is the name used to define the types of pinsused in the master key system. For example, even bitting willuse pins numbered zero, two, four, six, and eight. Odd bit-ting will use pins numbered one, three, five, seven, and nine.

Cross Keying. This term defines the ability of one change keyto intentionally open more than one lock. This is sometimesabbreviated by an X.

Hardware Schedule. This is a paperwork procedure in whichyou list all locking hardware and the keying schedule for alllocks in the system.

Master Key. The key that will open all locks within a masterkey system.

Grand Master Key. The key that will open all locks in twomaster key systems.

Great Grand Master Key. The key that will open all locks ina three master key system.

Great Great Grand Master Key. The key that will open alllocks in a four or more master key system.

Sectional Master Keying. A system where the master key sys-tem is enlarged by using different key blade keyway grooves to


prevent access of similarly cut keys into cylinders that arepinned alike within the system.

Now that you know a few important terms in the world ofmaster keying, let’s begin looking at the types of master keysystems available. These systems are categorized by level inthe locksmith trade.

Let’s begin with a level one system. Actually, a level one sys-tem requires no master keying at all. Each lock is assigned akey and only that key opens it. This is a typical system formost homes and small businesses.

A level two system is the first level to have a single masterkey. Any number of change keys may be available and eachchange key will open its own lock. One master key is presentin the system that will open all locks. This type of system isshown in Figure 43. A small apartment building might be oneexample of a level two master key system.

A level three sys-tem makes use oftwo separate masterkey systems. Withinthe systems, eachchange key willonly open the lockfor which it is in-tended. Two masterkeys are providedin this system witheach master keyable to open onlythe locks designedfor use with thatspecific master key.A grand master keyin this system is de-signed to open all

locks within the system. A level three master key system issuited to small motels where a housekeeper may receive amaster key for a certain group of rooms. A second house-keeper will receive the other master key for the other groupof rooms. The front desk clerk, however, would have thegrand master key to open any room in an emergency. Such alevel three master key system is shown in Figure 44.


FIGURE 43—A level twomaster key systemcontains any numberof change keys and asingle master key.

A level four master key system will use four or more masterkeys, two grand master keys, and a great grand master key.In this system, the change, master, and grand master keys op-erate in a similar manner as seen in a level three system. Thegreat grand master key will now be the key that will open alllocks within the master key system. Figure 45 displays thelevel four system. This type of system may be used in a hotelor school.

The final level we shall look at is the level five master keysystem. In a level five system, the level four system is dupli-cated and a great great grand master key has the ability toopen any lock within the system. As you can see in Figure 46,the level five system has at least four zones of change keysunder its control. Universities, large hospitals, and largeindustries may use this system.


FIGURE 44—A levelthree system will havea large number ofchange keys, a fewmaster keys and agrand master key.

Master Key System SecurityWhenever any lock can be opened by two or more keys, thesecurity of the lock is in jeopardy. This is especially true inextremely large systems where the number of keys becomesso large that the pins within the locks become very small. Itmay then be possible to “key pick” a lock. Key picking in-volves inserting a change key into a lock and then movingthe key up and down within the plug while placing turningpressure on the key. If the pins in the plug are small and thechange key is close in cut to the proper change key, thechances of opening a lock are quite good. Newer locks will bemore difficult where older, worn locks are rather easy to “keypick.” For this reason, it is always best to keep a master keysystem to the smallest size possible while allowing for somefuture expansion.


FIGURE 45—A level fourmaster key systemincorporates numerouschange keys andmaster keys, twogrand master keys,and a great grandmaster key.

How the System Works

Almost every master key system in use today uses the pintumbler type lock as the basis for the system. By now, you arevery familiar with how pin tumbler locks operate by raisingthe lower pin to the shearline. This action allows the plug toturn in the shell or cylinder opening the lock. A master keysystem will add more pins to the pin tumbler lock. Thesemaster pins will create a second point where a key can causea pin to be level with the shearline, allowing the plug to turn.

The master pins are the heart of this keying system. Up tothis point in this course, you have seen a maximum of six keycuts with five possible lower pin types. In a master key sys-tem, there are normally six or seven cuts in the change key ormaster key with an equal number of pin chambers in thetumbler and shell. Also, and most importantly, there can beup to nine different pin types allowing for a great number ofchange keys in the system.

In some master key systems, the difference in height betweenpins is 0.015 inches. In another system, the spacing is 0.023


FIGURE 46—A level fivemaster key systemperforms like twolevel four systemsside-by-side and hasa great great grandmaster key.


FIGURE 47—These are the master pins that are available in a 0.015 inch master key system.

FIGURE 48—Here arethe keys and pins froma single-pin chamberlock we will masterkey.

inches. In the 0.015 system, there will be nine possible pinsizes while in the 0.023 system, there are six pin sizes. A 0.015system is shown in Figure 47.

Let’s begin master keying a lock that has one pin chamber.Such a lock is shown in Figure 48.

This lock will use 0.015 inch type pins. Let’s give the masterkey, MK, a number four cut and say we want the change keyto have a number 7 cut. These keys are shown in (a). Nowlet’s set up the lock with shallower cut as shown in (b). Herewe insert the master key and insert a number four pin. Thepin reaches the shearline perfectly. Remove the master keyand insert the change key and replace the four pin with aseven pin. Once again the lock works perfectly.

In (c), you now have removed all pins and reinserted the numberfour lower pin. On the left side of the figure, the master key,once again, will operate the lock. Now remove the master keyand put the change key and add a number three master pin in


FIGURE 49—Here are the keys and pins from a two-pin chamber lock we will master key.

the pin chamber. Now the change key has its own shearlinemade by the addition of the number four lower pin to thenumber three master pin. Looking back to the left side dia-gram of Figure 48(c), notice how the number three master pinrides above the shearline when the master key is inserted intothis lock. The upper pins, UP, and springs are also shown in(c). Now, either the change key cut to a number seven or amaster key cut to a number four will open this lock.

Let’s continue looking at master key systems by adding a sec-ond pin chamber to our lock. This type of system is shown inFigure 49.

In this system, the master key will be cut as a five and two, aswe will invert the change key to a two and five cut key asshown in (a). In (b), the lock is pinned using standard pins.Here, both keys will act as change keys, only opening thelocks for which they are intended. In figure (c), the lower pinshave been converted to a master pin system. With the masterkey inserted into the plug, the number two pin along withthe number three master pin allow the plug to turn. Notehow the number three master pin rides above the shearline ofthe second pin chamber when this key is inserted. On theright side of figure (c), the change key has been inserted intothe lock. Now, since the change key is cut opposite to themaster key, the number three master pin rides above theshearline at the first cut in the change key.

This system of master keying looks rather simple, doesn’t it?All you are really doing is creating a lock with multiple pinsthat, in turn, create multiple shearlines within the lock. Tomake sure you understand this master keying process, let’slook at one more example.

Figure 50 gives us another example of a two-pin chambermaster key system. In this system, we will dedicate the mas-ter key as having a two-eight cut while the change key willhave a three-five cut in its blank.

In the (a) portion of the figures, you see the two precut keys.In figure (b), we have added the plug and the proper pins thatwould make either key a change key for this lock. Rememberthat if the pin setup were a two-eight or a three-five setup, onlyone of the keys would work in the plug. In figure (c), we haveplaced a number two pin in the first chamber and a numberone master pin above it. Now, either the master key or the


change key would raise the lower pin combination to one ofthe two possible shearline points. In the second chamber, wehave installed a number five pin and a number three masterpin. Again, either the master key or the change key will nowraise the pin combination to one of the twopossible shearlines. It’s that easy!

Of course, the locks you’ll be master keying will not be two-chamber pin tumbler locks. Most master key systems will usea standard key system that has six pin chambers and a keywith six spacings for the cuts.

A six-chamber pin tumbler master key system is not asdifficult as it may seem. To keep it simple, let’s look at anexample using two locks to be opened by a master key andtwo separate change keys. In this system, we will again use the0.015 inch pin system. Let’s use a master key with a key codeof 3, 4, 2, 4, 4, 2. The two change keys will have a code of 4, 5, 5,6, 5, 4 and 2, 0, 1, 0, 2, 3. Figure 51 shows this type of system.


FIGURE 50—Another example of keys and pins from a two-pin chamber lock is given here.

In (a), you can see a visual display of what the three keyswith these cuts would look like. We have selected the twochange keys to be greatly different in cut depths so that youcan see the extreme ends of a master key system withoutlooking at all of the keys in the middle of the system.

In (b), we begin loading the pin chambers with the necessarybottom pin. You will note that the smallest cut in any key isthe first position to receive a bottom pin. This is an importantrule in master keying. The smallest bitting, or pin, is alwaysloaded into the plug or pin chamber first.

In (c), we have completed the loading of the pin chambers.Notice how the change key with the deepest cuts has all ofthe lower pins and master pins below the shearline. The sec-ond change key with the most shallow cuts has the mostmaster pins above the shearline. Look also at the last cut inthe master key and the same cut in the second change key.This is the only location where the number of master pinsabove the shearline of the master key is greater than thoseabove the shearline of the second change key.


FIGURE 51—This illustration shows two change keys and a master key for a large six-pinchamber master key system.

The actual planning of a master key system is much simplerthan the process we have just gone through. In fact, a master keysystem can be ordered directly from the chosen lock manufac-turer. All you must describe to the lock manufacturer is

• The types of locks to be used

• The number of locks and change keys

• The number of master keys, grand master keys, greatgrand master keys and so forth

The lock manufacturer will then supply you with the locksand precut keys for the system you are working on.

Developing a Master Key System for a CustomerIn the event that you design and build a master key systemfor a customer, there are a few methods and rules to follow tomake system planning easier and more efficient. First let’slook at some of the rules.

Rule 1. In a very large system, no cut in any change keyshould match the cut in a master key in the position on thekey. For example, the master and change keys we justworked with are listed here.

MK 342442CK 455654CK 201023

Note how the master key and the change keys do not have asimilar cut in any one position. Now, let’s look at anotherexample. Let’s say we have the following master and changekey cuts.

MK (3)4244(4)CK (3)5565(4)CK 20102(4)

The numbers in parentheses are illegal numbers for change keyssince they have the same number as a master key in the sameposition. Change keys may duplicate two or more numberswithout a problem.

Rule 2. The depths between the successive cuts on a keyshould be no greater than seven for a 0.015-inch master pinsystem and five on a 0.023-inch system. This rule prevents a


very deep cut next to a shallow cut that can cause problemsduring keymaking. For example, a key with a code number

447019

would have an excessive depth change between the third andfourth cut and the fifth and sixth cut.

Rule 3. On a 0.015-inch system, there should be at least twocut sizes between successive cuts. (A 0.023-inch system is de-signed to allow single number changes.)

Rule 4. There should be no locks in the system set up withthe same number pattern.

Of all the rules presented, Rule 3 may be the most confusing.In a system that uses master pins in steps of 0.015, it’s veryeasy to key pick a lock with a change key that has similar cuts.If the system is set up with at least two pin size differencesbetween change keys, the overall pin difference expands to0.030—a difference that can prevent key picking. This doublespacing of the key cuts is often termed double step progression.

Locks that use master pins of 0.023 inch difference in dimen-sion can have keys with cut numbers just one value indifference. This method of keying a system is called singlestep progression.

In developing a master key chart for a customer, you willoften use a pin chart to define the chamber pinning of thelocks and the cutting of the master keys. Let’s use a two-chamber lock to look at a simple example of a pinning chart.

Looking back at Figure 49, the master key had a cut of fiveand two. We will use these numbers as the base numbers inthe chart shown here.

In this chart, wehave listed the evenbittings on the leftwith the odd bit-tings on the right.Now we can beginto list the changekeys that are possi-ble in the two-chamber system.


Chamber 1 Chamber 2

MK 2 54 76 98 10 3

Let’s first take the four in the left-hand column and combineit with the seven in the right-hand column to give us achange key of 4, 7. Next, let’s take the four of the first columnand combine it with the nine of the second column giving usa change key with the cuts 4, 9. If we continue using thismethod, your change keys with a four first cut would give us

4, 74, 94, 14, 3

Now we can begin combining the six cut with the numbers inthe second column to give us

6, 76, 96, 16, 3

Next, using the eight with the numbers in the right columnwe get

8, 78, 98, 18, 3

And finally, combining the zero with the numbers in theright column we get

0, 70, 90, 10, 3

Putting all these tables together gives us

4, 7 6, 7 8, 7 0, 74, 9 6, 9 8, 9 0, 94, 1 6, 1 8, 1 0, 14, 3 6, 3 8, 3 0, 3

But are all of these keys legal keys? According to our rules,especially Rule 2, there can be no more than seven cut depthsbetween successive key cuts. Therefore, the key 0, 9 is an ille-gal key and should be eliminated from the system.


Now you can see how a simple two-chamber pin tumbler lockcan give us 15 change keys and one master key. A six-chamberpin tumbler lock can give us many more combinations. In fact,using a six-chamber lock with a two-step system can give you4096 possible change keys and a master key. A single-step sys-tem can yield 15,625 keys! Of course, inside these locks wouldbe stacks of small master pins making the locks easier to pickthan a standard level one lock. For this reason, one general rulelocksmiths use on master key systems is to only place onemaster pin per chamber into each lock.

To show how one master pin per chamber would work, let’slook at a lock coded 4, 5, 3, 1, 4, 2. By adding a number onemaster pin to the first chamber, we get a master key andchange key codes 4, 5, 3, 1, 4, 2 and 5, 5, 3, 1, 4, 2. Now let’sadd a number two master pin to the second chamber of samelock. Our list of possible keys becomes

4, 5, 3, 1, 4, 25, 5, 3, 1, 4, 24, 7, 3, 1, 4, 25, 7, 3, 1, 4, 2

Now let’s add a third master pin to the third chamber. If it is anumber three pin, you would get the following key combinations:

4, 5, 3, 1, 4, 25, 5, 3, 1, 4, 24, 7, 3, 1, 4, 25, 7, 3, 1, 4, 24, 5, 6, 1, 4, 24, 7, 6, 1, 4, 25, 5, 6, 1, 4, 25, 7, 6, 1, 4, 2

This gives us eight possible combinations for three simplemaster pins. Note how the number of keys is doubling eachtime we add a new master pin. If we were to continue to thesixth chamber, we would have 64 keys and 63 different locks.However, our system with 63 locks and 64 keys has twoproblems. First, some of the change keys will have a cut thesame as the master key in at least one position. Often, thisbecomes an unavoidable situation when using a single masterpin in each chamber. Second, if a number one master pin is used,it becomes very possible to have change keys with cuts only onedigit apart. The solution to this second problem, when dealing


with a 0.015-inch master pin system, is to not use a numberone master pin in any chamber of a small master key system.

In order to reduce the chance of key picking, there is one“trick” locksmiths or lock manufacturers may use. For this ex-ample, let’s use a three story hotel with 60 rooms on each level.

Now, you can set up the 60 rooms on the first floor with 60 ofthe best pin combinations and key codes and a master key.You can then reuse these 60 pin combinations and key codeson the second and third floors. But wouldn’t this system al-low a first floor key to open a second and third floor lock? Itwould unless you change the keying of the locks from floorto floor. If the keyway changes, then the keys will not enterthe locks, rendering them useless except on the floor and forthe room they are intended.

The master key for all rooms would need to enter all of thesedifferent keyway grooves. Special master blanks are availablefor this purpose. In fact, it can be possible to create a levelthree or four system using locks with different keyways. Inthese systems, a master key can be created to fit only the key-way on one floor. A series of grand master keys can then becreated to open the locks on the first and second or secondand third floors. A great grand master key can be made toopen all locks in the entire hotel. All these keys can be madeusing the proper master blanks.

Selling a Master Key SystemA master key system will basically sell itself to your cus-tomer. Your customer will need such a system and you willhave the equipment to fill that need.

To create a master key system for a customer, the first step isto ask your customer a series of questions.

1. How many locks will be included in the system?

2. What type of lock is to be used?

3. Does the architect, owner, or builder have any prefer-ence to the manufacturer of the locking system?

4. How many change, master, grand master keys, and soforth will be required in the system?


5. Does the customer require duplicate change keys?

The answers to these questions will identify the exact size ofthe master key system to be put into place. It would now be asimple process to go into the manufacturer’s master key sys-tem books and price sheets to develop a hardware scheduleand estimated price for the job. If you have any problems insetting up the system, the manufacturer’s sales engineers canbe contacted for assistance.

In some master key systems, certain options may be desired byyour customer. One popular option is the use of constructionchange keys. These keys are used during the construction ofthe building to open specific locks. Once construction is com-plete, a special key is used to render the construction keys use-less. This feature is performed by adding pressed carbon orgraphite master pins into one or more chambers of the lock.The special key crushes these pins, rendering the construc-tion keys useless after the carbon or graphite pins are broken.



Locking It Up! 4

1. How many master keys are available in a level two master keysystem?

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2. Why should there be at least two cut sizes between successive cutson all change keys in a master key system?

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3. What type of step progression system is used with a master keysystem using 0.023 inch master pins?

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4. What type of pin can be used in a lock so that a constructionchange key can be rendered useless after construction is complete?

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THE KEY TO SUCCESS

Well, you’ve finished another information-packed study unitand learned many new and valuable skills. Key duplicationand rekeying are the most-often performed locksmithingservices. Once you’ve mastered these skills, you’ll be well onyour way to your goal of becoming a professional locksmith!

Now, review the text material if you need to, and then pro-ceed to the examination. Good luck!

KEY POINTS TO REMEMBER

Key duplication is the process of making a new key to matcha customer’s original. A new key is cut from a key blank (anuncut key) using either hand tools or a key cutting machine.

When duplicating a key by hand, a locksmith will find thefollowing tools useful: a small bench vise, softjaws, a felt-tippedmarking pen, a scribe, metal files, and a vernier caliper. Keyduplication by hand requires several steps. These steps are

1. Select the proper key blank.

2. Clamp the original key and the key blank together in a vise.

3. Match and mark the areas to be cut.

4. Cut the duplicate key.

5. Inspect the duplicate to be sure it matches the original.

6. Debur the duplicate key.

A key machine can also be used to quickly and accuratelyduplicate most types of keys. A key machine operates like abasic tracing machine. The sample key is placed in themachine’s left-hand vise, and a blank key is placed in theright-hand vise. The motor is turned on, and the machine’sguide moves along the original key, guiding the cuttingwheel over the blank to create an exact duplicate.

Key codes are code numbers that allow a locksmith to make anew key for a lock without having an original key to copy. Thecode numbers refer to the exact cut depths needed to create a


duplicate key. Although a key can be cut by hand once itscodes are known, normally keys are made using a specialtype of key cutting machine called a code cutting machine.

The term rekeying means to change the inside of a lock to fit anew key. Rekeying is a common service provided by lock-smiths every day. Rekeying is often performed when a cus-tomer purchases a home or a used car for which the originalowner may have retained a set of keys. The rekeying of locksis less expensive than the purchase of new locks.

Rekeying a lock will require you to perform the followinggeneral steps.

Step 1. Remove the plug according to the manufacturer’s in-structions for the lock you’re working on.

Step 2. Place the plug in your vise.

Step 3. Remove each disk or pin from the plug, and placethem in a tray in the order in which you remove them.

Step 4. Change the order of the disks or pins and replacethem in the plug.

Step 5. Cut a key to match the new arrangement of disks orpins.

Step 6. Reinsert the plug into the shell.

Step 7. Test the new key to make sure it works.

A master key system is a key system in which individual keysopen certain locks and one master key opens all of thoselocks. Hotels, motels, apartment buildings, universities, andother such large establishments often will use a master keysystem. This system allows individual access to certain roomsor areas using specific keys and total access to all areas by se-curity personnel using master keys.


Do You Know Now. . .

Below are the answers to the questions asked at the beginning of this studyunit.

What does the key code 2, 4, 1, 3, 5, 2 mean?

These numbers can be used with a spacer or guide key to cut the proper depths ina key for a disk tumbler, side bar wafer, or pin tumbler lock.

What is a plug follower?

A plug follower is used to remove the plug from a lock while retaining the upperpins and springs in the shell or cylinder.

What is a great great grand master key?

A great great grand master key can open any lock in a level five master keyingsystem.


1

1. d

2. Filing with a rocking motion

3. A vernier caliper can measure akey blade.

2

1. Six

2. To provide proper cut spacing onthe blank key

3. Code Number 4, dimension 0.175

4. Start at the cut nearest to theshoulder and continue cutting to-wards the tip of the key.

3

1. You drill a hole to gain access to aplug retainer.

2. It means copper and stands for anumber one wafer.

3. No, you only file the lower pins ona pin tumbler lock.

4. You remove the cylinder by loos-ening a set screw and unscrewingthe cylinder from the lockingmechanism.

4

1. One master key is available.

2. To prevent “key picking” by a keycut somewhat similar to the actualkey meant to open the lock

3. The single step progression systemcan be used.

4. A pressed carbon or graphite pin

Locking It Up! Answers

69

NOTES

70 Locking It Up! Answers

Practical Examination Answer Sheet 71

Important Instructions for Practical Exercises03180200 and 03180300

In addition to your regular examination for Study Unit 6, there are two practical exerciseswith this unit. The first exercise (03180200) is Duplicating a Cylinder Key for the PapaizPadlock. The second practical exercise (03180300) is Rekeying a Kwikset Lock.

These exercises will be sent to our locksmith consultants to be reviewed and graded.This takes extra time, so please be patient. To expedite the return of your graded exer-cises, please follow these directions carefully:

Specific instructions for each exercise begin on page 75 and continue through page 89.Read these instructions thoroughly before beginning the exercises.

Both exercise 03180200, Duplicating a Cylinder Key for the Papaiz Padlock, and exer-cise 03180300, Rekeying the Kwikset Lock, must be submitted together for grading.

After completing both practical exercises, remove the practical exercise answer sheetsAnswer the appropriate

questions on the answer sheet and include it with your submission.

You must include all of these items:

Completed answer sheet for both exercises

Papaiz padlock

Original and duplicated Papaiz keys

Rekeyed Kwikset lockset

Original and miscut Kwikset keys

Do not include any other examinations with these exercises.

You must send these exercises in the special shipping box (PM0007) provided. Use ofa different shipping container may cause additional delay in the grading and return ofyour exercises. Please contact our Customer Service Department if you did not receivethis shipping container.

Tape your keys together and secure them inside the box to prevent damage or loss.Once the carton is sealed, it cannot be opened without tearing it. Do not seal it until youhave placed all items in it. Address your lock projects to: Education Direct, 925 Oak St.,Scranton, PA 18515. (In Canada: 610-245 Victoria Ave., Westmount, QC H3Z 2M6)You are responsible for paying the postage. Be sure to put your return address andstudent number on the box. Our locksmith consultants will evaluate your work andreturn your grades to you as soon as possible. Please be patient.

on pages 73 and 74 from the binder and fill out the top portion.

72 Practical Examination Answer Sheet

NOTES

Professional Locksmith

Practical Exercise Answer Sheet 03180200

Name:________________________________________ Grade 03180200: _________

Address:______________________________________

City: _________________________________________

Phone Number: ________________________________

Student Number: _______________________________

❒ Check here if new address

03180200Practical Exercise:

Duplicating a Cylinder Key for thePapaiz Padlock

This exercise is based on the Papaiz Padlock cylinder key duplication. For this exercise,your key will be evaluated in each of the areas listed below.

1. Operation: Proper operation of the key in the padlock. Smooth operation of the key.(This part is worth a maximum of 60 points.)

2. Appearance: Even file cuts and angles. Uniform file cuts. Free of burrs or excessivelysharp edges. Cuts match the original key. Cuts that are smooth and clean. Appearancethat would be satisfactory to your customer. (This part is worth a maximum of 40points.)

Be sure to remove and complete both sides of this answer sheet and include them with bothpractical exercises of this unit.

Practical Examination Answer Sheet 73

Please Print Clearly For OfficeUse Only

State Zip

Grade 03180300_______

03180300Practical Exercise:

Rekeying a Kwikset Lock

This exercise is based on the rekeying of the Kwikset lock cylinder. You’ll be graded inthese areas:

Operation: The lock must operate smoothly and reliably with the extra miscut key provided.

Appearance: There must not be any damage to the lock surface or mechanism.

(Operation and Appearance are worth a maximum of 70 points.)

Answer the following questions in the space provided on this answer sheet. (Theseare worth 10 points each.)

1. What was the original combination of your Kwikset lock? ____________________

2. What is the combination of the new key provided? __________________________

3. What three tools are present in a rekeying or repinning kit that makes locksetrekeying a simple task?

_______________________

_______________________

_______________________

74 Practical Examination Answer Sheet

For OfficeUse Only

IntroductionKey duplication makes up a large portion of a locksmith’s busi-ness. People need keys for automotive, home, and businesslocks. Normally, the keys will be duplicated on a key cuttingmachine. However, in the event of machine failure, you shouldknow how to cut a key by hand using the techniques given here.

In this exercise, you’ll duplicate a key for your Papaiz cutawaypadlock. The lock uses a PZ1 key blank. This blank is includedin this package of materials. Locate the key blank now.

Your ToolsExcept for the black magic marker, all the tools and suppliesyou need for this exercise are included in this instructionpackage. The tools you’ll need for this exercise are

• Small bench vise

• Original key from the Papaiz padlock

• Key blank

• Metal files

• Black marker

Instruction Steps for Duplicating the KeyKey duplication will require several steps. These steps are

Step 1. Select the proper key blank.

Step 2. Blacken the key blank.

03180200 Practical Exercise:Duplicating a Cylinder Key forthe Papaiz Padlock

75

Step 3. Clamp the original key and the key blanktogether in a vise.

Step 4. Match and mark the areas to be cut.

Step 5. File the duplicate key.

Step 6. Inspect the duplicate to be sure it matches the original.

Step 7. Debur (smooth and polish) the duplicate key.

Step 8. Test the duplicate key in the lock to see if it works.

Since the key blank you need for this exercise is provided foryou, Step 1 is already complete. You can go on to Step 2,blackening the original key. Remember that you can useeither the smoking method or the marking pen method toblacken the key. When the key is completely blackened,move on to Step 3, clamping the keys in a vise.

Place the blackened original key in front of the key blank,align the keys exactly, then clamp them together in your vise.Tighten the vise handle just enough to hold the keys securelybetween the jaws. Excessive pressure will only deform thekeys. Make sure that all edges are even on the keys.

Now, prepare to start filing the key blank. Use thetriangular-shaped file from your file set. Starting at the cutnearest the bow, begin filing the key blank blade with slowforward motion cuts of your file. Remember to keep the filestraight and level, and don’t rock the file back and forth.When performing the filing, always make sure to cut only onthe forward stroke.

Continue filing until you begin to get near the metal of theoriginal key. File very carefully until the soot or ink is dis-turbed on the original key. Now stop! Cutting any deeperwill damage the original key.

When you are satisfied that the first cut is complete, move tothe next cut. Continue until you complete the last cut at thetip of the blade.

When you’re finished, the duplicate key should have thesame cut depths in the same locations as the sample key.After filing, the soot or ink should be barely disturbed at thesides and bottom of the key’s cuts.

76 Practical Exercise: Duplicating a Cylinder Key

Now, before removing the duplicate and original key fromthe vise, check the areas between the cuts on your duplicatekey. At this time, you should remove any sharp points be-tween the cuts. Remove all burrs on the back side of theblade. Inspect the key by measuring its cuts against the cutsin the original key.

Next, clean the original key completely of all soot or ink.Black marker may be somewhat difficult to remove once itdries. You can dip the key in a solvent such as nail polish re-mover to completely clean the blade of marking ink. To cleansoot from the original key, use a soft cloth or paper towel.

Checking the keys in the lock is a simple task. First, check thecondition of the original or sample key. If you did not cutinto the key cuts with the file during the duplication process,it should still operate the lock. Next, check your duplicatekey in the lock. Don’t force it. If there are problems with yourduplicate key, check it against the sample key.

If additional metal must be removed from the duplicate key,resoot or remark the original and return both keys to the vise.When you are satisfied the cuts in both keys match, clean anddebur them as previously mentioned and try each key againin the padlock.

Repeat the marking and filing steps until the duplicate oper-ates the lock. If you make a mistake, replace the damagedblank with the second blank provided for you and try again!

Practical Exercise: Duplicating a Cylinder Key 77

NOTES

78 Practical Exercise: Duplicating a Cylinder Key

IntroductionJust as with keymaking, rekeying can be a profitable aspect ofyour business. Many people buy used items, homes, automo-biles, and many businesses require new keys made whenemployees leave their jobs. Take for example a restaurant.They may have many refrigerators and freezers stocked withexpensive food products. If one of the managers leaves forother employment, the restaurant may want to rekey all of itslocks to prevent theft in the event the keys were duplicated.

Your ToolsWith the right tools and a knowledge of how a lock operates,rekeying is a simple task. All of the materials you’ll need forthis practical exercise are included in this instruction package.

These items include

• A Kwikset key-in-knob door lock, with two keys

• Another key that does not work in the Kwikset lock

• A professional pinning kit

Caution: If you open the pinning kit at this time, be carefulnot to spill all the small pins and parts inside!

• Cylinder removal tool

• A supply of top pins

• A supply of the various sizes of bottom pins

• A supply of springs

• A plug follower that fits all Kwikset lock cylinders

• A key gage for determining key cut depths

03180300 Practical Exercise:Rekeying a Kwikset Lock

79

Look now at the Kwikset key-in-knob door lock. In this exer-cise, you’ll learn how to remove the lock cylinder from thisdoorknob and how to rekey the lock plug. You’ll rekey thelock to fit the separate, single key found in this package.

Instruction Steps for Rekeying the Kwikset LockYour first task in this exercise is to determine the presentcombination of the lock. This can be done by measuring thekey’s cuts with the key gage provided in your pinning kit.Open the pinning kit and take out the key gage. Then, takethe original key for the Kwikset lock out of the box (that is, thekey that opens the lock now). Measure the key’s cuts with thekey gage as shown in Figure A. Start measuring at the cutnearest to the key’s bow. As you measure the key cuts, writedown the depths in the space provided here. (There are fivecuts altogether.)

_____________________________________________________________

Your second task is to determine the combination of the newkey (the combination that you’ll rekey the lock to). Take theother key provided in this package (the key that doesn’t workthe lock) and measure its cut depths with the key gage. Writethe depths in the space provided below.

_____________________________________________________________

80 Practical Exercise: Rekeying a Kwikset Lock

FIGURE A

This is the combination that you’ll rekey the lock to. Now,let’s begin the actual rekeying steps.

Looking at the doorknob, it may seem almost impossible toremove the cylinder! However, it’s actually very simple usingthe cylinder removing tool found in your pinning kit.

Step 1: The first step in rekeying is to remove the round spin-dle bar from the lockset. Insert the rounded end of the cylin-der removing tool and rotate the round spindle until the tabon the spindle lines up with the stem as shown in Figure B.

Once the tab is lined up with the threaded stem, insert therounded side of the cylinder removing tool between thelower stem and the spring clip housing as shown in Figure C.Note location of half round spindle.

Practical Exercise: Rekeying a Kwikset Lock 81

FIGURE B

FIGURE C

The rounded end of the tool should just come beneath the upperplate of the spring clip housing to strike the tab on the spring clip. Ifthe rounded end of your tool is on the spring or below the spring, itwill not free the spindle. With the clip properly pushed up with thetool, turn the lockset upside down and the spindle will drop out(Figure D). Set the spindle aside on your workbench.

Step 2: The next step is to use the opposite end of the removingtool to release the cylinder. Insert the forked end of the cylinderremoving tool as shown in Figure E. Align the tool with the twolong screw stems on either side of the spindle hole. Move the rearend of the tool back and forth to release both cylinder retaining


FIGURE D

FIGURE E

springs. Note the engagement of the forked end of the tool tothe two cylinder retaining springs in Figure F(b). Push thecylinder out of the knob.

Step 3: With the cylinder released, it is now time to extractthe plug from the cylinder. A small retaining clip or C-clip isused to hold the plug in the cylinder of this lock. The forked endof the cylinder removing tool can be used to start to remove thisring as shown in Figure G. Then, use the rounded end of the toolto pry the clip away from the plug (Figure H). However, becareful. Use your thumb to put inward pressure on the plug sothat it does not come free, causing you to dump all of thepins and springs out of the plug and cylinder.


FIGURE F

FIGURE G

Step 4: To remove the plug, place the original key into the plugand turn it about 90 degrees to the right. Next, place the plugfollower behind the plug (Figure I). Push lightly on the back ofthe plug follower, and extract the plug from the cylindershown in Figure J. Be careful not to lose any of the pins containedin the plug.


FIGURE I

FIGURE H

Step 5: When you are done removing the plug, you canclearly see the bottom pins in the plug. Carefully dump thesepins out of the plug into a tray or other receptacle (Figure K).Remove the key.

Step 6: Prepare the new pins you’ll need to rekey the lockplug. Remove the pins of the correct depths from your pin-ning kit and line them up in the correct order to be placed intothe plug (Figure L).


FIGURE J

FIGURE K

Step 7: Insert the new key into the plug (Figure M). Then, re-load the pin chambers with the new bottom pins (Figure N).As you drop in each pin, you can see whether the pin iscorrect for the cut on the key. The pin should fall in and lieexactly at the level of the shearline. If a pin is above or belowthe shearline, remove it and install the correct lower pin.When you are done rekeying, your plug should appear asshown in Figure O.


FIGURE L

FIGURE M

Step 8: When you are confident that all of the bottom pinsexactly match the cuts in the new key, reinsert the plug care-fully into the cylinder. Place the edge of the plug carefullyagainst the plug follower, and as you slowly insert the pluginto the cylinder, withdraw the plug follower.

Step 9: Hold the plug in the cylinder with your finger, andcarefully withdraw the key (Figure P).


FIGURE N

FIGURE O

Step 10: When the plug is installed and it rotates properlywithin the cylinder, you can begin reassembly of the cylinder.Replace the plug retainer clip at the rear of the plug (Figure Q).This clip will push on with finger pressure.

Step 11: Return the cylinder to the doorknob and snap it intoplace (Figure R).


FIGURE P

FIGURE Q

Step 12: Reinsert the spindle into the lockset (Figure S).

Step 13: Complete your work with the lock by testing thelock and key thoroughly to be sure that it works properly.


FIGURE R

FIGURE S

NOTES


925 Oak StreetScranton, Pennsylvania 18515-0001

Keymaking and Rekeying

When you feel confident that you have mastered the material in this study unit, complete the followingexamination. Then submit only your answers to the school for grading, using one of the examinationanswer options described in your “Test Materials” envelope. Send your answers for this examinationas soon as you complete it. Do not wait until another examination is ready.

Questions 1–20: Select the one best answer to each question.

1. What is the name used for the aluminum angle iron pieces used over vise jaws to pro-tect the shell or blank key from damage?

A. Face plates C. SoftjawsB. Soft faces D. Jaw pads

2. What is the proper cut depth for a disk tumbler lock with a cut code number of four?

A. 0.190 C. 0.220B. 0.205 D. 0.235

Examination 91

EXAMINATION NUMBER:

03100600Whichever method you use in submitting your exam

answers to the school, you must use the number above.

For the quickest test results, go to

http://www.takeexamsonline.com

http://www.takeexamsonline.com

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3. What type of process is normally used by a bit key blank manufacturer to create a bitkey blank?

A. The blanks are cast in molds.B. The blanks are drop forged.C. The blanks are machined on metalworking machinery.D. The blanks are formed in a press.

4. How do you remove the tailpiece from a rim cylinder lock?

A. Remove the two screws from the retainer plate.B. Turn the key completely around in the lock and pull out on the tailpiece.C. Drive a roll pin from the rear of the plug.D. Push in on the tailpiece as you turn the key until the tailpiece comes free of the plug.

5. Which of the following lubricants can be used on a lock?

A. Oil C. WD-40B. Grease D. Paraffin-based lubricant

6. How can you remove the cylinder of a mortise lock?

A. Remove the face plate and spring latch assembly, then remove the retainer for thecylinder.

B. Remove an Allen or other type of retaining screw and unscrew the cylinder from thehousing.

C. Remove the inner thumbturn and plate to gain access to the cylinder retaining plate.D. Push in on the spring latch and unscrew the cylinder from the housing.

7. Which one of the following levels of master keying has a grand master key at the highestlevel in the system?

A. Level one C. Level threeB. Level two D. Level four

8. You are working with a very large master key system. Your master key has a key codeof 3, 6, 4, 2, 5, 7. Which one of the following keys is an acceptable change key for thissystem?

A. 3, 4, 5, 4, 6, 2 C. 6, 6, 4, 3, 4, 5B. 4, 5, 6, 2, 5, 3 D. 5, 2, 2, 4, 3, 4

9. What type of device is often used to clean a file of built-up material?

A. Wire brush C. File pickB. Pen knife D. File card

92 Examination

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10. What type of instrument is used by locksmiths to measure key blades and key cuts?

A. Vernier calipers C. Steel ruleB. Micrometer D. Machinist’s rule

11. What type of file is most commonly used in duplicating a cylinder key?

A. Circular C. BoxB. Half round D. Triangular

12. You’re working with a 0.015 inch master key system. Which one of the following key cutcodes is acceptable?

A. 2, 4, 2, 6, 3, 5 C. 5, 5, 4, 3, 1, 1B. 3, 3, 4, 2, 4, 2 D. 2, 8, 0, 4, 7, 1

13. What is the name used for the key that is placed in the right-hand vise of a code cuttingmachine and sets the spacing of the cuts on the blank key?

A. Basic key C. Crown keyB. Guide key D. Stationary key

14. You have a change key with a key code 3, 5, 7, 4, 2, 6. If you add a number three mas-ter pin to the first chamber, what other key could open this lock?

A. 0, 5, 7, 4, 2, 6 C. 3, 5, 7, 4, 2, 9B. 6, 5, 7, 4, 2, 6 D. 3, 5, 7, 4, 2, 3

15. What type of tool is used to keep the upper pins and springs in position in the shell orcylinder when you are removing the plug from the lock for rekeying?

A. Spanner wrench C. Plug followerB. Allen wrench D. Sectional plug

16. You’ve begun code cutting a key for an automobile and have completed your first codecut which was a number two cut of 0.225 inches. Now you must make a number four cutof 0.175 inches. How far should you move the micrometer’s reading from the first cut?

A. 0.100 C. 0.050B. 0.075 D. 0.025

Examination 93

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17. You begin measuring an older automotive key and find the measurements to be:

Cut Measurement

1 0.1392 0.2373 0.1924 0.2175 0.1936 0.165

What key code should you cut the new key to?

A. 5, 1, 3, 2, 3, 4 C. 5, 2, 3, 3, 4, 4B. 5, 1, 3, 3, 3, 4 D. 5, 1, 2, 3, 3, 5

18. A disk tumbler lock is brought to you for rekeying. Its original key was coded 4, 4, 3, 4, 5,4. Which disks should you swap to rekey this lock?

A. First and second C. First and fifthB. First and fourth D. First and last

19. What is the distance in inches between code numbers for automotive keys?

A. 0.015 C. 0.023B. 0.020 D. 0.025

20. What is meant by “key picking” a lock?

A. Using a duplicate master key to open a lock.B. Using a grand master key from one system to open a lock in a second system.C. Using a master blank to create a universal master key.D. Using a change key that is close to the proper change key to open a lock.

94 Examination

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COMING ATTRACTIONS

In your next study unit, we’ll be examining the differenttechniques used to open locks when no keys are available.These techniques include lockpicking, lock reading, keyimpressioning, shimming, and emergency lock forcing. Thisstudy unit will also include two more hands-on practicalexercises that will help you develop more valuable lock-smithing skills. Keep up the good work, and enjoy your nextlessons!


study unit 6 keymaking and rekeying - auto locksmith usa · theory of code key cutting reading...

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