Split pin 1

Split pin

A split pin (UK usage) / cotter pin (USA usage)holding a rod in place with a washer.

A split pin, also known in U.S. usage as a cotter pin or cotter key,[1]

is a metal fastener with two tines that are bent during installation,similar to a staple or rivet. Typically made of thick wire with ahalf-circular cross section, split pins come in multiple sizes and types.

The British definition of "cotter pin" is equivalent to U.S. term"cotter", which can be a cause for confusion when companies of bothcountries work together. There are signs that manufacturers andstockists are increasingly listing both names together to avoidconfusion; this led to the term split cotter sometimes being used for asplit pin.

Construction

Split pins: A: New B: Installed C: Spring type D:Cross-section of traditional design

A new split pin (see figure A) has its flat inner surfaces touching formost of its length so that it appears to be a split cylinder (figure D).Once inserted, the two ends of the pin are bent apart, locking it in place(figure B). When they are removed they are supposed to be discardedand replaced, because of fatigue from bending.[2]

Split pins are typically made of soft metal, making them easy to installand remove, but also making it inadvisable to use them to resist strongshear forces. Common materials include mild steel, brass, bronze,stainless steel, and aluminium.[3]

Types

As shown above, there are different types of ends available on split pins. The most common is the extended prongwith a square cut, but extended prongs are available with all of the other types of ends. The extended prong type ispopular because it makes it easier to separate the tines. To ease insertion into a hole the longer tine may be slightlycurved to overlap the tip of the shorter tine or it is beveled. The length, L, of the split pin is defined as the distancefrom the end of the shortest tine to the point of the eyelet that contacts the hole.[3]

Split pin 2

Hammer lock split pins are properly installed by striking the head with a hammer to secure the pin. This forces theshorter tine forward, spreading the pin.[4]

• Standard• Humped• Clinch

SizesThe diameter of split pins are standardized. American split pins start at 1⁄32 in and end at 3⁄4 in.[4]

Metric split pin sizes[5]

Nominal diameter [mm] Hole size [mm] For bolt size [mm]

1.5 1.9 6

2 2.4 8

2.5 2.8 10

3 3.4 12, 14

4 4.5 20

5 5.6 24, 28

6 6.3 30, 36, 42

8 8.5 48

American split pin sizes[4] [5]

Nominal diameter [in] Hole size [in] For bolt size [in]

1⁄323⁄64

3⁄641⁄16

1⁄165⁄64

1⁄45⁄64

3⁄325⁄16

3⁄327⁄64

3⁄87⁄64

1⁄81⁄8

9⁄641⁄2

9⁄645⁄32

5⁄85⁄32

11⁄643⁄4

3⁄1613⁄64

1, 1.125

7⁄3215⁄64

1.25, 1.375

1⁄417⁄64

1.5

5⁄165⁄16

1.75

3⁄83⁄8

7⁄167⁄16

Split pin 3

1⁄21⁄2

5⁄85⁄8

3⁄43⁄4

Applications

A car hub showing a castellated nut cover andsplit pin (near center).

Split pins are frequently used to secure other fasteners, e.g. clevis pins,as well as being used in combination with hardboard discs as atraditional joining technique for teddy bears.[6]

Split pins may be used in some applications as low-tech shear pins. Acommon application of this is when used to secure a castellated nut.One problem with this type of use is that the castles on the nut mustline up with the hole in the mating part so that the split pin can beinstalled. When the nut is torqued properly, but the holes still do notline up, it is preferable to over-tighten the nut than under-tighten it.[7]

References[1] U.S. Patent 4298299 (http:/ / www. google. com/ patents?vid=4298299)[2] Welsch 2005, p. 141.[3] Soled 1957, p. 312.[4] Cotter pins (http:/ / www. sizes. com/ tools/ cotter_pins. htm), , retrieved 2009-08-17.[5] Jensen 2001, p. 234.[6] Baby Pip Teddy Bear (http:/ / www. craftbits. com/ viewProject. do?projectID=1524) at CraftBits.com[7] Reithmaier 1999, p. 151.

Bibliography• Jensen, Cecil Howard (2001), Interpreting Engineering Drawings (http:/ / books. google. com/

?id=n5AZcpo5IFcC) (6th ed.), SteinerBooks, ISBN 9780766828971.• Reithmaier, Lawrence W. (1999), Standard aircraft handbook for mechanics and technicians (http:/ / books.

google. com/ ?id=a3bloqOeFhkC) (6th ed.), McGraw-Hill Professional, ISBN 9780071348362.• Soled, Julius (1957), Fasteners handbooks (http:/ / books. google. com/ ?id=8OdSAAAAMAAJ), Reinhold

Publication Corporation.• Welsch, Roger (2005), From Tinkering to Torquing: A Beginner's Guide to Tractors and Tools (http:/ / books.

google. com/ ?id=J_xMHJSIvL0C), MBI Publishing Company, ISBN 9780760320822.

Article Sources and Contributors 4

Article Sources and ContributorsSplit pin  Source: http://en.wikipedia.org/w/index.php?oldid=438445597  Contributors: A2Kafir, AKGwikiAcct, AMCKen, Alex holden, Altafqadir, Anthony Appleyard, Ashawley, Atlant,Bejnar, Castor8, Charles Matthews, Chris Cross, ClairSamoht, Daderot, Dogcow, Esradekan, Globbet, Gpvos, Graibeard, Jj137, Jsd, Justallofthem, Kamezuki, Kelisi, Kivaan, LilHelpa, Mdrag,Memestream, Modica4uall, Neclark, Peridon, Pissant, Pjbflynn, Polyparadigm, Royalbroil, Shaddack, Skipweasel, Someonesdad363616, Techtonik, Themightyseptopus, Wazronk, Wizard191,Zephyris, 26 anonymous edits

Image Sources, Licenses and ContributorsFile:Cotter Pin (PSF).png  Source: http://en.wikipedia.org/w/index.php?title=File:Cotter_Pin_(PSF).png  License: unknown  Contributors: Pearson Scott ForesmanImage:CotterPins.svg  Source: http://en.wikipedia.org/w/index.php?title=File:CotterPins.svg  License: Public Domain  Contributors: KivaanFile:Cotter pin ends.svg  Source: http://en.wikipedia.org/w/index.php?title=File:Cotter_pin_ends.svg  License: Creative Commons Attribution-Sharealike 3.0  Contributors: Wizard191Image:Car hub cotter pin.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Car_hub_cotter_pin.jpg  License: Creative Commons Attribution-ShareAlike 3.0 Unported  Contributors:1-1111, Ies, Leonard G., Polyparadigm, Tano4595, 2 anonymous edits

LicenseCreative Commons Attribution-Share Alike 3.0 Unportedhttp:/ / creativecommons. org/ licenses/ by-sa/ 3. 0/