Cotter Pins

Cotter Pins

Cotter pins are small, bent metal pieces that hold together a wide range of equipment. They pass through a drilled hole on a bolt or shaft and lock the joint against vibration, giving you peace of mind during operation. With cotter pins and other fastening pins from Tractor Supply, you’re prepared for work in the field or shop.

Compact Locking Pieces for Moving Assemblies

Cotter pins are specialized fasteners that use shape rather than threads to keep components together. Farmers and mechanics most commonly reach for them for applications where vibration would work a plain nut loose. Low-carbon steel cotter pins handle most jobs because the metal is strong yet simple to bend during installation. Zinc plating provides rust protection for outdoor rigs, and stainless versions offer protection for marine or wet groundwork where regular steel gives up fast. Sizes in our selection range from 1/32 in. for hobby use to 3/8 in. for trucks and farm equipment, so there’s a cotter that suits your Life Out Here.

Standard Prong Styles

On equipment that stays put for long stretches, the classic cotter pin design with a rounded loop and two straight legs is a reliable choice. Push the pin through, then bend the prongs apart with pliers to keep the assembly from loosening. The rounded top provides a solid grip when the pin must be removed later for service. Typical diameters run from 1/16 in. up to 1/4 in., with leg lengths scaled to shaft thickness – longer legs handle thicker shafts.

Hairpin Clip-On Options

For jobs that require frequent assembly and disassembly, the hairpin cotter pin is ideal. It snaps on and off by hand, with the clip holding the workpiece securely under tension. You can easily remove and reset it using gloves for safety. Hairpins work especially well with clevis pins on power take-off (PTO) tractor attachments. If you often change out your equipment, keeping a collection of hairpin cotter pins nearby is a smart move.

Pick Up Cotter Pins from Tractor Supply

A cotter pin is a small part in terms of size, but a missing or faulty one can cause equipment failures. Our hardware stock features cotter pins in a handful of variations, sizes and constructions for quick projects and large farm equipment alike. Browse our selection on our website or head over to your local Tractor Supply store to take home what you need the same day.