applying heat treating processes applying heat treating processes

Applying Heat Treating Applying Heat Treating ProcessesProcesses

Interest ApproachInterest Approach

I am going to heat this piece of metal I am going to heat this piece of metal with my gas torch. with my gas torch.

Once the metal is hot, what can I Once the metal is hot, what can I now do with this piece of metal and now do with this piece of metal and why?why?

Is there a connection here for Is there a connection here for treating metals with heat?treating metals with heat?

Student Learning ObjectivesStudent Learning Objectives

Identify the tools and equipment used for Identify the tools and equipment used for hot metal work.hot metal work.

Explain the processes of measuring and Explain the processes of measuring and holding metal.holding metal.

Describe the methods of heating, cutting, Describe the methods of heating, cutting, squaring, drawing out, upsetting, squaring, drawing out, upsetting, bending, twisting, and punching holes in bending, twisting, and punching holes in hot metal.hot metal.

Student Learning ObjectivesStudent Learning Objectives

Describe the heat treating Describe the heat treating processes: hardening, tempering, processes: hardening, tempering, and annealing.and annealing.

Identify the safety practices to follow Identify the safety practices to follow when working with hot metal.when working with hot metal.

TermsTerms

Annealing steelAnnealing steel CementiteCementite FerriteFerrite Hardening steelHardening steel MartensiteMartensite PearlitePearlite Tempering steelTempering steel

What are the tools and What are the tools and equipment used for hot equipment used for hot

metal work?metal work?

There are several pieces of There are several pieces of equipment used for hot equipment used for hot

metal work.metal work.

Hot Metal ToolsHot Metal Tools

Equipment used in the heating of Equipment used in the heating of stock may be a gas welding/cutting stock may be a gas welding/cutting torch, a carbon arc torch, a forge, a torch, a carbon arc torch, a forge, a furnace or a stove.furnace or a stove.


A forge is the most economical way A forge is the most economical way to heat large areas of metal.to heat large areas of metal.


When the metal to be heated cannot When the metal to be heated cannot be removed from a machine, or be removed from a machine, or when the area to be heated is small, when the area to be heated is small, a gas welding/cutting torch or a a gas welding/cutting torch or a carbon arc torch can be used.carbon arc torch can be used.

TorchTorch

When heating with the gas When heating with the gas welding/cutting torch or carbon arc welding/cutting torch or carbon arc torch, care must be exercised torch, care must be exercised because of the intense heat.because of the intense heat.

If too much heat is used, the metal If too much heat is used, the metal may oxidize and checking of the may oxidize and checking of the metal may occur.metal may occur.


Anvils and bases are a necessity in Anvils and bases are a necessity in hot metal work and are also used in hot metal work and are also used in other repair jobs, such as bending, other repair jobs, such as bending, straightening, cutting, and riveting straightening, cutting, and riveting cold metal.cold metal.

Anvils and BasesAnvils and Bases

The anvil should be of good quality; The anvil should be of good quality; otherwise, the steel face will crack otherwise, the steel face will crack and chip.and chip.

Anvils and BasesAnvils and Bases

Various types of anvil bases are Various types of anvil bases are used; chunks of wood, masonry, or used; chunks of wood, masonry, or metal frames with the top of the anvil metal frames with the top of the anvil at a convenient working height. at a convenient working height.

If concrete or metal frames are used, If concrete or metal frames are used, a two inch block of wood should a two inch block of wood should separate the anvil from the base to separate the anvil from the base to serve as a cushion.serve as a cushion.


The cutting edge of the anvil hardy is The cutting edge of the anvil hardy is similar to a cold chisel. similar to a cold chisel.

It has a square shank that fits into It has a square shank that fits into the hardy hole of an anvil and is the hardy hole of an anvil and is used to cut both hot and cold metal.used to cut both hot and cold metal.


The anvil fullers are used for making The anvil fullers are used for making grooves and rounding inside corners grooves and rounding inside corners and angles, and fits into the hardy and angles, and fits into the hardy hole of the anvil.hole of the anvil.

The anvil swages are used to shape The anvil swages are used to shape round or oval objects.round or oval objects.


Blacksmith’s hammers, used only Blacksmith’s hammers, used only with one hand, range in weight from with one hand, range in weight from 1 to 14 lbs., with a 1.5 to 2 lb. used 1 to 14 lbs., with a 1.5 to 2 lb. used for most jobs.for most jobs.


Blacksmith’s sledges require the use Blacksmith’s sledges require the use of both hands and are used for of both hands and are used for heavy bending and shaping. heavy bending and shaping.

Weights range from 5 to 20 lbs., Weights range from 5 to 20 lbs., however an 8 lb. sledge is big however an 8 lb. sledge is big enough for most jobs.enough for most jobs.


Hot cutters have handles, can be Hot cutters have handles, can be purchased with cutting edges of purchased with cutting edges of different widths, and are used to cut different widths, and are used to cut metal that has been heated. metal that has been heated.

A hot cutter is generally used when A hot cutter is generally used when a helper is available to do the a helper is available to do the striking.striking.


Handled punches are made with Handled punches are made with round and square points and are round and square points and are used for punching holes in hot metal.used for punching holes in hot metal.


Flatters are used to remove hammer Flatters are used to remove hammer marks and to make the surface of marks and to make the surface of the metal smooth and flat. the metal smooth and flat.

A magnet is necessary to determine A magnet is necessary to determine when the metal is hot enough to lose when the metal is hot enough to lose its magnetic properties.its magnetic properties.


Set hammers are used for making Set hammers are used for making square, sharp corners and square, sharp corners and shoulders. shoulders. –They are placed on the metal and They are placed on the metal and

struck with a hammer or sledge.struck with a hammer or sledge. Small metal squares are used to Small metal squares are used to

measure stock and to check right-measure stock and to check right-angle bends.angle bends.


Tongs come in many shapes and Tongs come in many shapes and sizes for hot metal work, the most sizes for hot metal work, the most common are straight-lip for flat metal common are straight-lip for flat metal and bolt for round stock.and bolt for round stock.

A strong heavy-duty machinist’s vise A strong heavy-duty machinist’s vise with six inch jaws is necessary for with six inch jaws is necessary for the heavy bending and shaping of the heavy bending and shaping of hot metal.hot metal.

How is metal measured and How is metal measured and held?held?

In order to measure and work In order to measure and work metal satisfactorily, the stock metal satisfactorily, the stock

must be securely and properly must be securely and properly held.held.

Measuring stockMeasuring stock

Measuring stock is very important. Measuring stock is very important.

In construction work it is best to In construction work it is best to secure a plan or a blueprint, if secure a plan or a blueprint, if possible, which will indicate exact possible, which will indicate exact dimensions.dimensions.


Measure the required length and Measure the required length and mark with chalk. mark with chalk.

If the piece is to be heated, the mark If the piece is to be heated, the mark must be made with a center punch must be made with a center punch or a file because a chalk mark will or a file because a chalk mark will burn off.burn off.


If a bent piece of metal is to be If a bent piece of metal is to be duplicated, take a lightweight piece duplicated, take a lightweight piece of wire and follow the bends with the of wire and follow the bends with the wire.wire.

Then remove the wire, straighten it, Then remove the wire, straighten it, and measure its total length.and measure its total length.

The wire should be placed near the The wire should be placed near the center of the piece being measured.center of the piece being measured.


The amount of material required for The amount of material required for making a ring is 3.5 times the making a ring is 3.5 times the diameter of the ring plus ½ the diameter of the ring plus ½ the diameter of the stock.diameter of the stock.

In measuring a piece to be welded, In measuring a piece to be welded, add the length needed for upsetting add the length needed for upsetting to the total length needed.to the total length needed.

After the stock to be worked has After the stock to be worked has been marked it must be properly been marked it must be properly

held.held.

Select tongs which fit the work. Select tongs which fit the work.

–The jaws should be parallel when The jaws should be parallel when clamped on the stock. clamped on the stock.

–If necessary, heat the jaws to a If necessary, heat the jaws to a cherry red and bend them to fit and cherry red and bend them to fit and hold the stock firmly.hold the stock firmly.


held.held.

Keep the tongs cool by dipping them Keep the tongs cool by dipping them frequently in water.frequently in water.

Be careful not to bend the jaws or Be careful not to bend the jaws or handles of the tongs.handles of the tongs.


held.held.

There are several different kinds of There are several different kinds of tongs, but only a few are frequently tongs, but only a few are frequently used in agricultural mechanics. used in agricultural mechanics.

–The type of tongs to use depends The type of tongs to use depends upon the kind of work that is to be upon the kind of work that is to be done.done.

TongsTongs

Flat-jawed tongs with a lengthwise Flat-jawed tongs with a lengthwise groove in the middle of each jaw groove in the middle of each jaw help hold materials securely.help hold materials securely.

Link tongs with a crosswise groove Link tongs with a crosswise groove in the jaws help in holding links, in the jaws help in holding links, rings, and similar materials.rings, and similar materials.

TongsTongs

Bolt tongs have a curved opening in Bolt tongs have a curved opening in the jaws. the jaws.

–This permits the holding of round This permits the holding of round or square materials.or square materials.

How is metal heated, cut, How is metal heated, cut, squared, drawn out, upset, squared, drawn out, upset,

bent, twisted, and hole bent, twisted, and hole punched?punched?

Proper procedures must be Proper procedures must be followed to properly heat, cut, followed to properly heat, cut, square, draw out, upset, bend, square, draw out, upset, bend, shape, twist, and hole punch shape, twist, and hole punch

metal.metal.

Heating MetalHeating Metal

When heating metal, heat should be When heating metal, heat should be applied to all parts of the metal being applied to all parts of the metal being fabricated.fabricated.

Heating in one spot may cause Heating in one spot may cause damage to the metal due to uneven damage to the metal due to uneven expansion.expansion.


Do not use excessive air or oxygen Do not use excessive air or oxygen in heating. in heating. –This will cause the metal to scale, and This will cause the metal to scale, and

increase the time required for heating.increase the time required for heating. Working any metal heated to less Working any metal heated to less

than a cherry red may cause it to than a cherry red may cause it to crack.crack.


Wrought iron and low carbon steel Wrought iron and low carbon steel can be heated to a white heat for can be heated to a white heat for shaping. shaping.

–If the heated part sparkles, cut off If the heated part sparkles, cut off that part because its value has that part because its value has been destroyed.been destroyed.


Tool steel or high carbon steel Tool steel or high carbon steel should be heated only to a cherry should be heated only to a cherry red to prevent cracking the metal, red to prevent cracking the metal, damaging the grain structure, and damaging the grain structure, and destroying the carbon content.destroying the carbon content.


Malleable cast iron cannot be heated Malleable cast iron cannot be heated above 1,375°F, because it will revert above 1,375°F, because it will revert to some of the characteristics of to some of the characteristics of white cast iron when cooled.white cast iron when cooled.

Hot metal may be cut with a hot Hot metal may be cut with a hot chisel, a hardy and a cutter, an chisel, a hardy and a cutter, an

oxyacetylene cutting torch, or an oxyacetylene cutting torch, or an electric arc.electric arc.

Hot Metal CuttingHot Metal Cutting

Hot chisels and cutters are used for Hot chisels and cutters are used for cutting generally large and heavy cutting generally large and heavy metals.metals.

Hot Metal CuttingHot Metal Cutting

When cutting a light piece of When cutting a light piece of material, often it is not necessary to material, often it is not necessary to use the cutter. use the cutter. –Merely place the stock over the hardy Merely place the stock over the hardy

and deliver hammer blows directly to and deliver hammer blows directly to the stock.the stock.

When squaring hot metal When squaring hot metal follow these set procedures:follow these set procedures:

1. Mark the piece to be squared with 1. Mark the piece to be squared with a file, using a steel square.a file, using a steel square.

2. Heat the piece to a cherry red 2. Heat the piece to a cherry red color. color. –Only a small portion should be heated; Only a small portion should be heated;

other-wise, the piece may enlarge other-wise, the piece may enlarge when it is struck on its end.when it is struck on its end.


3. Place the piece over an anvil, and 3. Place the piece over an anvil, and hammer it. hammer it. –Be sure that the face of the hammer Be sure that the face of the hammer

falls parallel with the face of the anvil.falls parallel with the face of the anvil.

4. Continue to hammer, turning the 4. Continue to hammer, turning the piece until it is square.piece until it is square.


5. Reheat to a cherry red color if the 5. Reheat to a cherry red color if the piece becomes cool before it is piece becomes cool before it is squared.squared.

Drawn Out ProcedureDrawn Out Procedure

When a piece of iron or steel is When a piece of iron or steel is pounded so that it is longer and pounded so that it is longer and smaller in diameter, it is said to be smaller in diameter, it is said to be drawn out. drawn out.


This procedure is as follows:This procedure is as follows: 1. Heat the portion of the stock to be 1. Heat the portion of the stock to be

enlarged to a white heat.enlarged to a white heat. 2. Place the stock on the anvil in a 2. Place the stock on the anvil in a

perpendicular position, forming right perpendicular position, forming right angles to the face of the anvil to angles to the face of the anvil to prevent the stock from bending.prevent the stock from bending.


3. Strike the cold end of the stock with 3. Strike the cold end of the stock with hard blows. hard blows. –If the stock bends, place it over the anvil If the stock bends, place it over the anvil

and straighten it.and straighten it.

When metal is upset, it is placed When metal is upset, it is placed on end and hammered until it is on end and hammered until it is enlarged and shortened to the enlarged and shortened to the

correct size.correct size.

Metal Upset ProcedureMetal Upset Procedure

1. The metal must be heated 1. The metal must be heated uniformly over the entire section to uniformly over the entire section to prevent it from increasing in size at prevent it from increasing in size at one point.one point.

2. Strike the metal with a sharp, well-2. Strike the metal with a sharp, well-directed blow so the entire heated directed blow so the entire heated section will be upset uniformly.section will be upset uniformly.

One of the important phases One of the important phases of metal work is the bending of of metal work is the bending of materials.materials.

Bending ProceduresBending Procedures

1. Small pieces often may be bent 1. Small pieces often may be bent cold, but some pieces should be cold, but some pieces should be heated before they are bent.heated before they are bent.

Bending ProceduresBending Procedures

2. Square and angle bends can be 2. Square and angle bends can be made by placing the heated metal made by placing the heated metal over the edge of the anvil and over the edge of the anvil and hammering the end down along the hammering the end down along the side. side. –Clamp one end of the metal in a heavy Clamp one end of the metal in a heavy

vise and bend it against the jaws.vise and bend it against the jaws.

Hot metal may be twisted by Hot metal may be twisted by clamping one end in a vice clamping one end in a vice and turning the other end with and turning the other end with a wrench.a wrench.

Twisting ProcedureTwisting Procedure

1. To make a long twist without 1. To make a long twist without bending the metal, slip a piece of bending the metal, slip a piece of pipe over the metal between the vise pipe over the metal between the vise and the wrench.and the wrench.

Twisting ProcedureTwisting Procedure

2. The length of the twist will be 2. The length of the twist will be determined by the distance between determined by the distance between the vise jaws and the wrench.the vise jaws and the wrench.

Holes are punched in hot Holes are punched in hot metal with the handled punch.metal with the handled punch.

Hole Punch ProcedureHole Punch Procedure

1. The end of the punch must be 1. The end of the punch must be kept flat and the sides shaped so the kept flat and the sides shaped so the corners or edges will be sharp.corners or edges will be sharp.–In most cases a helper is needed to In most cases a helper is needed to

strike the punch with a larger hammer strike the punch with a larger hammer or sledge.or sledge.


2. To punch a square hole lay out 2. To punch a square hole lay out and center punch the location of the and center punch the location of the hole.hole.

3. Heat the metal to nearly white.3. Heat the metal to nearly white. 4. Quickly place the metal flat on the 4. Quickly place the metal flat on the

face of the anvil. face of the anvil. –Center the end of the punch over the Center the end of the punch over the

mark.mark.


5. Strike the head of the punch with 5. Strike the head of the punch with a sledge, driving the point about two-a sledge, driving the point about two-thirds of the way through the piece. thirds of the way through the piece. –The punch should be cooled frequently The punch should be cooled frequently

in water to prevent drawing its temper in water to prevent drawing its temper and upsetting its end.and upsetting its end.


6. Turn the piece over, and then set 6. Turn the piece over, and then set the punch directly over the hole that the punch directly over the hole that was started from the other side.was started from the other side.


7. Drive the punch in from this side 7. Drive the punch in from this side until almost through. until almost through. –Then, slide the metal over the round Then, slide the metal over the round

hole of the anvil to allow the metal to hole of the anvil to allow the metal to be punched completely to the same be punched completely to the same size from the top side.size from the top side.

How is metal hardened, How is metal hardened, tempered, and annealed?tempered, and annealed?

Heat treating steel includes Heat treating steel includes hardening, tempering, and hardening, tempering, and

annealing.annealing.

Hardening SteelHardening Steel

Hardening steel is making it hard by Hardening steel is making it hard by heating it to a light cherry red and heating it to a light cherry red and then cooling it quickly in warm water.then cooling it quickly in warm water.

Steel HardeningSteel Hardening

The hardness of steel is determined The hardness of steel is determined by two factors: the amount and type by two factors: the amount and type of carbon present in the steel and of carbon present in the steel and the heat-treating process used in the heat-treating process used in hardening the steel.hardening the steel.

Steel HardeningSteel Hardening The presence of carbon affects the The presence of carbon affects the

physical properties most; however, physical properties most; however, carbon content and heat treatment go carbon content and heat treatment go together.together.–Carbon content will change the physical Carbon content will change the physical

properties only slightly without heat properties only slightly without heat treatment. treatment. Heat treatment would have little effect if not Heat treatment would have little effect if not

for the carbon content of the steel.for the carbon content of the steel.

Steel HardeningSteel Hardening

Carbon is important to the treating Carbon is important to the treating process. process.

During heat treatment, carbon atoms During heat treatment, carbon atoms can bond or link up with iron atoms can bond or link up with iron atoms to form new compounds with to form new compounds with different physical properties.different physical properties.

Basic elemental iron is called Basic elemental iron is called ferrite.ferrite.

When ferrite has carbon dissolved in When ferrite has carbon dissolved in it, a new form, cementite or iron it, a new form, cementite or iron carbide will form.carbide will form.

Cementite is usually found in a Cementite is usually found in a mixture with ferrite. mixture with ferrite.

The resulting mixture is called The resulting mixture is called pearlite, because it is pearly white pearlite, because it is pearly white crystals.crystals.

PearlitePearlite

Steel that has not been heat treated Steel that has not been heat treated is pearlite.is pearlite.

Steel can be hardened by heat Steel can be hardened by heat treatment because pearlite, when treatment because pearlite, when heated to 1,320–1340°F, then heated to 1,320–1340°F, then quickly cooled by warm water quickly cooled by warm water becomes martensite.becomes martensite.

PearlitePearlite

The steel takes an intermediate The steel takes an intermediate form, austenite, during heating form, austenite, during heating above 700°F.above 700°F.

MartensiteMartensite

Austenite forms martensite upon Austenite forms martensite upon quick cooling. quick cooling.

Martensite is a new substance with a Martensite is a new substance with a crystal structure that gives steel its crystal structure that gives steel its hardness.hardness.

The more martensite present, the The more martensite present, the harder and more brittle the steel.harder and more brittle the steel.

Tempering steelTempering steel

Tempering steel is reheating Tempering steel is reheating hardened steel to obtain the desired hardened steel to obtain the desired hardness and toughness.hardness and toughness.


The second heating is to a lower The second heating is to a lower temperature which must be very temperature which must be very carefully controlled. carefully controlled. –This is to allow some of the hard This is to allow some of the hard

martensite to revert to its original martensite to revert to its original pearlite form. pearlite form.

–Then the steel is cooled slowly or Then the steel is cooled slowly or quenched in warm water.quenched in warm water.


The process of changing martensite The process of changing martensite back to pearlite is dependent on back to pearlite is dependent on heat increase, usually within one of heat increase, usually within one of three of the following ranges:three of the following ranges:


The first range is obtained by The first range is obtained by reheating the steel to a temperature reheating the steel to a temperature between 200 and 400°F. between 200 and 400°F.

Steel that is heat treated to this Steel that is heat treated to this temperature retains most of its temperature retains most of its original hardness but does gain original hardness but does gain some strength and toughness.some strength and toughness.


The second range is obtained by The second range is obtained by reheating the steel to a temperature reheating the steel to a temperature between 400 and 700°F. between 400 and 700°F.

In this range steel is moderately In this range steel is moderately hard and moderately tough.hard and moderately tough.


The third range is between 700 and The third range is between 700 and 1,000°F. 1,000°F.

Steel reheated to this temperature Steel reheated to this temperature range retains only a little of its range retains only a little of its original hardness; however, it original hardness; however, it becomes very strong and tough.becomes very strong and tough.

Annealing steelAnnealing steel

Annealing steel is softening the Annealing steel is softening the metal and removing the brittleness.metal and removing the brittleness.

The annealing process allows The annealing process allows hardened or tempered steel to be hardened or tempered steel to be made soft so it can be filed, cut, or made soft so it can be filed, cut, or shaped.shaped.


To anneal a piece of steel, heat it To anneal a piece of steel, heat it until all the steel is in the austenite until all the steel is in the austenite form, light cherry red or above form, light cherry red or above 1,320°F, depending on the carbon 1,320°F, depending on the carbon content. content.


Then allow it to cool slowly in an Then allow it to cool slowly in an insulating material such as insulating material such as vermiculite. vermiculite.

This allows the austenite to be-come This allows the austenite to be-come soft pearlite instead of martensite.soft pearlite instead of martensite.

What are the safety practices What are the safety practices to be followed when working to be followed when working

with hot metal?with hot metal?

Observe the following general Observe the following general safety practices for working safety practices for working

hot metal.hot metal.

Safety PracticesSafety Practices

Obtain the instructor’s permission Obtain the instructor’s permission before using any tool or machine.before using any tool or machine.


Wear industrial quality eye Wear industrial quality eye protection to protect eyes from protection to protect eyes from sparks and metal chips.sparks and metal chips.


To protect against burns, wear To protect against burns, wear clothing such as coveralls, high-top clothing such as coveralls, high-top shoes, leather aprons, and leather shoes, leather aprons, and leather gloves. gloves.

Remove all paper from pockets, and Remove all paper from pockets, and wear cuff-less pants.wear cuff-less pants.


Protect hair and scalp by restraining Protect hair and scalp by restraining long hair and wearing a cap.long hair and wearing a cap.

Safety PracticesSafety Practices In the event of an emergency, all In the event of an emergency, all

students involved in or observing the students involved in or observing the emergency should call for help emergency should call for help immediately. immediately.

You should know the location of fire You should know the location of fire extinguishers and fire blankets and how extinguishers and fire blankets and how to use them. to use them.

You should also know the approved You should also know the approved procedure for exiting the laboratory.procedure for exiting the laboratory.


Report all injuries or accidents to the Report all injuries or accidents to the instructor immediately, no matter instructor immediately, no matter how slight.how slight.


Keep the work area and tools clean. Keep the work area and tools clean. Dirty, greasy, and oily tools and Dirty, greasy, and oily tools and

floors can cause accidents. floors can cause accidents. Clean and put away all unneeded Clean and put away all unneeded

tools and materials. tools and materials. Clean up oil spills and scrap metal Clean up oil spills and scrap metal

from the floor and equipment.from the floor and equipment.


Always use the right size tool and Always use the right size tool and only for its intended purpose. only for its intended purpose.

Use tongs or pliers for carrying hot Use tongs or pliers for carrying hot metal.metal.


Loud talking, as well as, pushing, Loud talking, as well as, pushing, running, and scuffling while working running, and scuffling while working with hot metal can cause serious with hot metal can cause serious accidents. accidents.

Keep your mind on your work.Keep your mind on your work.


Work in a well-ventilated area. Work in a well-ventilated area.

Fumes and intense heat are a part Fumes and intense heat are a part of hot metalwork and require that of hot metalwork and require that work be done outdoors or in a work be done outdoors or in a forced-ventilated area.forced-ventilated area.


When lifting heavy objects, obtain When lifting heavy objects, obtain help.help.

Lift with the legs and not the back. Lift with the legs and not the back.

Straining to lift heavy objects can Straining to lift heavy objects can cause serious injury.cause serious injury.


To avoid the possibility of accidental To avoid the possibility of accidental burns, keep hot metal in a safe place burns, keep hot metal in a safe place until it cools. until it cools.

Use tongs or pliers for handling hot Use tongs or pliers for handling hot metal.metal.


Before leaving the laboratory or work Before leaving the laboratory or work station, make certain the heat station, make certain the heat source is shut off and cool.source is shut off and cool.


Do not perform hot metalwork on Do not perform hot metalwork on wood floors or near flammable wood floors or near flammable materials.materials.

Never work on containers that have Never work on containers that have been used for storage of been used for storage of combustible material.combustible material.


Keep cables and hoses from Keep cables and hoses from coming in contact with hot metal and coming in contact with hot metal and sharp objects. sharp objects.

Never point a flame at cables or Never point a flame at cables or hoses.hoses.


Use warm water instead of Use warm water instead of quenching oil for quenching. quenching oil for quenching.

Quenching oil is easily confused with Quenching oil is easily confused with other oils.other oils.

ReviewReview

Identify the tools and equipment used for Identify the tools and equipment used for hot metal work.hot metal work.

Explain the processes of measuring and Explain the processes of measuring and holding metal.holding metal.

Describe the methods of heating, cutting, Describe the methods of heating, cutting, squaring, drawing out, upsetting, squaring, drawing out, upsetting, bending, twisting, and punching holes in bending, twisting, and punching holes in hot metal.hot metal.

ReviewReview

Describe the heat treating Describe the heat treating processes: hardening, tempering, processes: hardening, tempering, and annealing.and annealing.

Identify the safety practices to follow Identify the safety practices to follow when working with hot metal.when working with hot metal.

applying heat treating processes applying heat treating processes

Documents

approach n

hot metal tools n equipment

n weights n weights

hot metal tools n anvils

hot metal work

cold metal

student learning objectives

metal frames