How to Select Industrial Pins   Industrial pins information info Industiral pin types categories

Image credit: Anchor Bolt Supply; Unison Tek Co.; Misumi

 

Industrial pins are varieties of fastening hardware meant to couple, align, mount, assemble, or penetrate two workpieces. The operation of the pin depends on design and employment, but industrial pins can be categorized into several categories, such as: hitch and linch pins; cotter pins and wire clips; spring pins; locating and fixturing pins; and specialty pins.

 

Industrial Pin Operation

Hitch pins are designed to couple mating components--such as a vehicle and trailer--often employing a locking mechanism. Indeed, many types of cotter pins achieve this function, but are intended for lower stress ratings and shear rates. Cotter pins and wire clips are also used to maintain components within an assembly, which is similar to a linch pin's function on a wheel axle.

 

Dowel pins are designed to affix two components together, often including an adhesive, by a firm fit with predrilled holes. This is similar to locating pins, except locating pins are designed for easier removal and positioning.

 

Spring pins have an expandable diameter that assumes the diameter of the insertion hole. It is a type of self-retaining fastener, alike to an expanding diameter pin, a type of specialty pin. Shear pins, another type of specialty pin, have functions that are commonly filled by cotter pins.

 

Industrial Pin Production

Pin manufacturing depends on the type of material. Metal is the most common material choice for industrial pins, due to its strength, precision, and functionality—and metal industrial pins are produced via roll forming.

Industrial pin production info graphic

Image credit: Timken Co.

 

  • Hardened and ground steel undergoes a heat treatment process that compacts carbon atoms, resulting in a stronger but more brittle version of the metal. If uncoated, it is likely to oxidize under certain conditions.

  • Unhardened steel is more malleable and less expensive, but also cannot handle extreme loads. It is vulnerable to corrosion.
  • Stainless steel is corrosion resistant, aesthetically appealing, and exceptionally strong, but is also more expensive than other steel options.
  • Brass provides quality strength, conductivity, corrosion resistance, and low-magnetic permeability, but is limited to a lower working load.
  • Monel® is a proprietary metal blend with good corrosion resistance, strength, but is expensive and difficult to form.
  • Aluminum is light, ductile, conductive, and very resistant to oxidation.
  • Titanium is strong, with good temperature and corrosion resistance. It is 44% lighter than steels. 

Some industrial pins are made of plastic, which can be manufactured to close tolerances, but does not have the strength of metal.  Plastic industrial pins are injection molded.

Video credit: Society of Manufacturing Engineers

 

Finally, industrial pins may be made from wood. This is especially true for dowel pins which are frequently used in furniture; they can be sanded, stained, and painted for decorative purposes. Wooden materials must be milled, which can result in imperfections and dissimilar workpieces. They are processed on the same type of mill that handles fence posts.

Video credit: Montana Hydraulics

 

Industrial Pin Configurations

Individual categories and pin types can be better assessed in their selection guides, linked in the table below.

 

Pin Type

Image

Description

Dowel Pins

Drive pin

Drive pin

Image credit: RCP Crawlers

Drive pins have an interference fit and must be driven into place. They are commonly used to assemble components in rotary or other moving applications.

Groove pin

Groove pin

Image credit: Nordex Inc.

Grooved pins are cylindrical pins with longitudinal grooves. They are used to join two components. Grooves provide greater surface area for adhesive, and offer improved holding power.

Knurled pin

Knurled Pin industrial dowel hardware fasten

Image credit: TRP Truck & Trailer Parts

Knurled pins are straight pins with a knurled surface. They provide a better grip than a smooth dowel pin.

Oversize dowel pin

Oversized Industrial Dowel Pin

Image credit: Drillspot

Oversized dowel pins are manufactured slightly over the nominal size.

Parallel pin

Parallel Industrial Dowel Pin

Image credit: Ekotherma

Parallel pins are cylindrical dowel pins that have the ends machined to two different tolerances.

Pull dowel pin

Pull dowel pin industrial

Image credit: ABC Fastener Group Inc.

Pull dowel pins have a threaded hole in one end so that a screw can be inserted to help remove the pin from a blind hole.

Spiral groove pin

Industrial spiral groove dowel pin

Image credit: C and H Hardware

Spiral groove pins are cylindrical pins with longitudinal grooves. They are used to join two components. Grooves provide greater surface area for adhesive, and offer improved holding power.

Straight dowel pin

Straight industrial pin dowel

Image credit: Hartford Technologies

Straight dowel pins are cylindrical pins that join two pieces together to prevent motion or slippage.

Stepped dowel pin

Stepped dowel industrial pin

Image credit: AmericanMuscle.com

Stepped dowel pins have two different body diameters.

Taper pin (nonthreaded)

Tapered pins 

Image credit: Ravi Engineering Co.

Nonthreaded taper pins are solid pins with a taper at a rate of 1/4" per foot from the larger end to the smaller end.

Taper pin (threaded)

Threaded taper pins industrial info selection

Image credit: Senior Graphics Limited

Threaded taper pins have the same dimensions as standard taper pins with the addition of a threaded section, usually at the smaller end. Threaded taper pins are used when removal may be required.

Undersize dowel pin

How to Select Industrial Pins Undersize dowel

Image credit: Apex Fasteners

Undersized dowel pins are manufactured slightly under the nominal size.

Spring Pins

Coiled spring pin

Coiled industrial spring pin

Image credit: Apex Fasteners

Coiled spring pins are made of steel or other metal. They are coiled into a hollow cylindrical shape.

Roll/slotted spring pin

Slotted spring pin

Image credit: Apex Fasteners

Roll pins or slotted steel springs are made of rolled steel or other material and rolled into a cylindrical shape. These headless, hollow pins have a slot that runs longitudinally down the length of the pin.

Cotter Pins and Wire Clips

Circle cotter pin

Circle cotter pin industrial

Image credit: Drillspot

Circle cotters are manufactured from wire that is wound or turned-on from the middle out. The open end of the cotter is threaded into a hole in a pin, and then turned until it snaps into place.  Circle cotters are very secure. They are used where sharp ends are not permitted, such as fabric applications.

Clinch pin

Clinch hump pin industrial fastener hardware

Image credit: Western Wire

Clinch pins are a variation of cotter pins. They are manufactured with a hump on one end. Clinch pins are self-securing and do not require bending of the ends.

Extended cotter pin or hammerlock cotter pin

Select types cotter pins industrial

Image credit: Smew

Cotter pins are split pins that are opened outward after passing through a hole. The most common type is the extended cotter pin, which has one end that is slightly longer than the other. Often, cotter pins are used in conjunction with clevis pins. Cotter pins are also referred to as split pins.

Hairpin clip

Hairpin clips 

Image credit: F.C. Mason Co.

Hairpin clips are reusable pins that are also referred to as external hitch pin clips. Hairpin clips  have an asymmetrical bulb and wave on one half of the pin. The other half of the pin is straight. This type of pin assembles components between the cavity created by the waved and straightened ends, with the assembly held tight by the pin's elastic deformation. These are used to quickly assemble or disassemble components.

Hairpin cotter pin

Hairpin industrial shear fastener removable

Image credit: Reilly Supply Co.

Hairpin cotters are reusable pins that are sometimes called hitch pin clips or external hairpin clips. With hairpin cotters, one end of the pin is inserted in the hole of a hitch pin. A hump on the other side clips the pin externally.

Ring cotter pin

How to Select Ring Industrial Cotter pins

Image credit: Wilson Mfg. Co.

Ring cotter pins are a hybrid between a twist pin and a circle cotter. One side of the wire clip is kept straight, while the other side is helixed over and under the straightened side, before terminating with a final bend across the straight side. This helix and twist method provides an automatic, secure lock when components are threaded appropriately.

Safety pin

Safety industrial pins

Image credit: Rainbow Spring Industries

Safety pins are wire-wound, and similar in construction to household fasteners by the same name.

Twist pin

Twist clip industrial pin

Image credit: Speeco

Twist pins are twisted wire pin clips that can be used as replacements for standard hairpin cotters. Twist pins are self-locking, and easy to install and remove.

Hitch Pins and Linch Pins

Clevis pin

Clevis pin industrial hardware

Images credits: U.S. Industrial Fasteners of Arizona

Clevis pins are used with cotter pins. They have a head on one end and a hole on the other. The hole is used to insert the cotter pin. Clevis pins are removable and used to secure two components together.

Clevis pin (adjustable)

How to Select Adjustable Clevis Pins

Images credits: Fastenal

Adjustable clevis pins are similar to standard clevis pins, but have several holes at different dimensions from the end in order to accommodate a range of fastening applications.

Detent pin

Detent pin 2 balls spring lock

Image credit: Primary Fasteners

Detent pins have a locking ball that holds the pin in place by spring force. The spring pushes the ball axially to the pin, allowing it to seat in a hole or detent.

Hitch pin

Hitch pins with hairpin lock

Image credit: Aubuchon Co. Inc.

Hitch pins are used to temporarily couple or "hitch" two components. They are used with a cotter pin or integral safety pin. Usually, hitch pins are manufactured with a wire loop grip at one end for easy removal.

Linch pin

Select linch pins

Image credit: Quoteflections

Linch pins have a ring loop attached to the head. This loop snaps down hard to hold the fastener in place.

Toggle pin

Toggle pin industrial fastener locked profile

Image credit: Titan

Toggle pins are a type of locking hitch pin that does not require a cotter pin. Instead, they have a spring-loaded toggle on the end to keep the pin from sliding out.

Wire lock/snapper/safety spring pin

Snapper wire lock safety spring pin

Image credit: Power Sports Network

Wire locks, snappers, and safety spring pins are various types hitch pins. They contain an integral wire-locking device. These pins may also have a spring for positive-locking.

Locating and Fixturing Pins

Bullet-nose dowel

Industrial bullet-nose dowel pin

Image credit: Carr Lane

Bullet-nose dowels are precision locating pins with a long tapered nose. They are often used with a mating bushing, or liner. Bullet-nose dowels are similar to bullet-nose pins, but have a smaller locating shoulder.

Bullet-nose pin

Bullet-nose pin fixturing dowel pin

Image credit: Carr Lane

Bullet-nose pins are used to align two pieces of a fixture. They have a short, round, or diamond tip. Bullet-nose pins are used with a mating bushing or liner that provides a precision fit with the nose of the pin. Often, round and diamond bullet-nose pins are used together. In these cases, the round pin is the primary, 2-axis locator and the diamond pin is the secondary, 1-axis locator.

Clamping pin

How to Select Clamping pins

Image credit: Carr Lane

Clamping pins are used to clamp materials of varying thicknesses. They are adjusted with a collar, or positioned with a bushing and brazing.

Cone locator pin

Cone locator pin

Image credit: Carr Lane

Cone locator pins are similar to round and diamond locating pins, but have cone-shaped tips. They are used with a mating bushing, or liner, for medium-accuracy location. Cone locator pins can compensate for a great deal of misalignment.

Diamond locating pin

Diamond locating pin

Image credit: Carr Lane

Diamond locating pins have a 4-flat, diamond shaped tip. They are used to accurately locate a part, often in conjunction with a round pin. Diamond pins have either a small or large locating shoulder.

Drift pin

Industrial drift pin

Image credit: Klein Tools

Drift pins are tapered pins. They are used to align holes in members that will be bolted together.

Floating locating pin

Select Industrial Pin Floating Locating

Image credit: Carr Lane

Floating locating pins are very similar in function to diamond pins. They are used to provide precise, 1-axis location while floating in the perpendicular axis. Typically, a floating locating pin is used in conjunction with a round pin to locate in two axes.

Indexing/pop pin

Industrial locating index/ pop pin

Image credit: Riteon Corp.

Indexing pins or pop pins are spring-loaded devices. They usually have a knob or handle for gripping, and for ease of installation and removal. Indexing pins may be threaded or nonthreaded.

L-pin

L-pins industrial locating fixturing alignment

Image credit: Carr Lane

L-pins are removable alignment or locating pins with an L-shaped handle at one end. 

Quick-release pin

Select industrial quick release pin

Image credit: Jergens Inc.

Quick-release (ball lock) pins use a spring-loaded steel ball to provide a positive lock. A button or other actuating device unlocks the balls for easy removal.

Round locating pin

Selecting information industrial locating fixturing round pin

Image credit: Carr Lane

Round locating pins have a round, tapered tip. They are used to accurately locate a part, often in conjunction with a diamond pin.  Round pins have either a small or large locating shoulder.

T-pin

T-Pin

Image credit: Carr Lane

T-pins are removable alignment or locating pins with a T-shaped handle at one end.

Specialty Pins

Ejector pin

Industrial ejector pins sleeves

Image credit: DME

 

Ejector pins are small pins that are used to push or eject a part or material.

Escutcheon pin

Escutcheon pins

Image credit: Noah's Marine Supplies

Escutcheon pins are used for light fastening jobs such as attaching nameplates. Escutcheon pins have a semispherical head at one end and a long cone at the other and are usually hammered into place by hand.

Expanding diameter pin

Expanding diameter pin industrial info selection specs

Image credit: Carr Lane

Expanding diameter pins have a clearance fit in their relaxed state, and segments that spread when a cam is actuated to provide a snug fit. They can be easily installed and removed.

Pivot/hinge pin

Select pivot hinge pin

Image credit: Bimba

Pivot pins are used to attach two pivoting or hinged components.

Shear pin

Shear pin industrial

Image credit: Emhart Technologies

Shear pins are designed to break if the fastened members move, under stress, in opposite parallel directions to their mating surfaces.

Weld pin

Industrial weld pins

Image credit: Drillspot

Weld pins are designed to be welded into place.

 

Resources

 

How to Select Hitch and Linch Pins

 

How to Select Cotters Pins and Wire Clips

 

How to Select Dowel Pins 

 

Spring Pins Information

 

How to Select Locating and Fixturing Pins

 

Specialty Pins Information