Pins

How to choose pins

• Function: Use dowel pins for accurate alignment or to share shear load between parts. Use cotter pins to lock a clevis pin or castellated nut after assembly.
• Diameter & hole fit: For dowel pins, pick a nominal diameter, then choose a press fit for permanent alignment or a slip fit where removal is needed. For cotter pins, match the pin to the drilled hole the hardware provides.
• Material & environment: Stainless steel for corrosion resistance, zinc-plated or plain steel for general indoor use, brass for non-magnetic or cosmetic needs.
• Length & grip: Dowel length should fully span the joint with engagement in both parts. Cotter length should allow both tines to bend back over the part after insertion.
• Strength & service: Choose hardened steel dowels for high shear or repeated locating. Use stainless cotter pins where moisture is present.

Common sizes, materials & finishes

• Dowel pins: Typical diameters from 1/16 in to 1/2 in, common lengths from 1/4 in to 3 in. Materials include 18-8 and 316 stainless steel, alloy or carbon steel, with plain or passivated finishes.
• Cotter pins: Typical diameters from 1/32 in to 1/4 in, lengths from 1/2 in to 4 in. Materials include low-carbon steel, 18-8 or 316 stainless, and brass, with plain or zinc-plated finishes.

Typical applications & industries

• Machinery and fixtures, jigs, and tooling alignment
• Automotive, ag, and equipment linkages using clevis pins
• Furniture, cabinetry, and assembly lines needing repeatable location
• Marine and outdoor assemblies using stainless components

Installation & best practices

Dowel pins

1. Deburr and clean the mating holes. Verify size tolerance for press or slip as required.
2. Support the part and press the pin squarely using an arbor press. Avoid hammering to prevent mushrooming.
3. For slip-fit locating, install dowels in the base part and use slip holes in the mating part for easy assembly.

Cotter pins

1. Insert the tines through the drilled hole of the shaft or clevis pin until the head seats.
2. Spread the tines in opposite directions with pliers to lock the hardware. Trim only if necessary to avoid snagging.

Troubleshooting & pro tips

• Pin walks out: Hole oversize or misaligned. Ream to a known size and use a press-fit dowel, or replace worn components.
• Galling during installation: Lubricate lightly, confirm interference is within spec, and press instead of hammering.
• Corrosion at joints: Choose 316 stainless in marine or chemical exposure, or isolate dissimilar metals.
• Cotter pin breaks at bend: Select a larger diameter or stainless material, and bend gradually with pliers rather than sharply at the same spot.

Why buy Pins from AlbanyCountyFasteners.com

• Wide selection of stainless and steel dowel pins and cotter pins with popular diameters and lengths
• Corrosion-resistant options for outdoor and marine environments
• Bulk quantity price breaks and fast shipping from our U.S. warehouse
• Technical product pages and responsive support to help you choose correctly