--- title: "What Are Split Cotter Pins Used For?" description: "Split Cotter Pins (ISO 1234 / DIN 94) are used for precise location and light shear duty between two parts. Catalogued 0.6 mm to 13 mm." url: https://engineeringhardware.com/applications/split-cotter-pins/ source: Engineering Hardware & Fasteners --- # What Are Split Cotter Pins Used For? Pins · ISO 1234 / DIN 94 · Application guide Typical applications, the industries that specify split cotter pins, and how to choose the right size, material and finish for the joint. Split Cotter Pins are used for precise location and light shear duty between two parts. They are manufactured to ISO 1234 / DIN 94, and selection is driven by the nominal diameter, the fit and tolerance the assembly requires, and the service environment. - **Primary duty:** Precise location and light shear duty between two parts - **Governing standard:** ISO 1234 / DIN 94 - **Nominal diameter range:** 0.6 mm to 13 mm - **Category:** Pins Application notes are general engineering guidance. Verify the property class and any approval requirement against your own design calculation. ![What Are Split Cotter Pins Used For? application image](https://engineeringhardware.com/wp-content/uploads/2026/06/Split-Cotter-Pins-—-ISO-1234-／-DIN-94-Applications1.webp) Application guide for Split Cotter Pins to ISO 1234 / DIN 94. The core duty of the type is precise location and light shear duty between two parts. The typical industries, the how-to-specify checklist, assembly practice and the exclusion cases are set out below. Stocked across roughly 0.6 mm to 13 mm, they cover general to heavy-duty work. ## Typical Applications for Split Cotter Pins The most common settings where these are specified: - **Jigs & fixtures:** precise location of tooling plates and locating features. - **Linkages & hinges:** pivot points carrying light shear. - **Machine alignment:** dowelling mating housings so they reassemble in the same position. - **General machine building:** fastening covers, brackets, motors and sub-assemblies on production equipment. - **Maintenance & repair (MRO):** a stocked size for servicing existing plant where the original fastener spec must be matched. ## How to Specify Split Cotter Pins for Your Application - **Size:** Select on nominal diameter, then on the hole tolerance and fit class — the fit, not the diameter alone, determines whether the part locates or slips. This product spans 0.6 mm–13 mm; check the full table below for the exact dimensions of each size. - **Material:** Choose the material and finish for the service environment — plated steel for general use, stainless for corrosion resistance. - **Environment:** For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient. - **Standard:** This product is supplied to ISO 1234 / DIN 94. Quoting the standard on your order guarantees interchangeable dimensions between suppliers. ## Installation & Assembly Practice - Ream the hole to the specified fit class; a dowel pressed into a drilled-only hole will not locate accurately. - Press pins in with steady force rather than hammer blows where possible, and chamfer the hole entry. ## Common Selection Mistakes with Split Cotter Pins - Using a dowel pin as a load-carrying shear bolt — dowels locate, they are not sized for sustained shear. - Ignoring the fit class: a locational fit and an interference fit need different hole tolerances. ## Where Split Cotter Pins Are Not the Right Choice Not for carrying significant tensile or repeated heavy shear loads — use a bolt or a keyed joint for that. Custom manufacturing · Made to drawing ## Need a split cotter pins outside the standard range? Diameter, length, tolerance class, hardness and end form are specifiable. Ground diameters are held after heat treatment rather than before. Made by cold heading or turning. Minimum order from 2,000 pieces; samples within 7 days of drawing approval. [Custom pin manufacturing](https://engineeringhardware.com/custom/pins/)[Send a drawing](https://engineeringhardware.com/custom/pins/#rfq) ## Technical Drawing Dimensioned line drawing of 0.6 Split Cotter Pins to ISO 1234 / DIN 94. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected. - **Hole dia min (mm):** 0.7 - **Hole dia max (mm):** 0.9 - **Common length range (mm):** 6~16 - **Material:** Low-carbon steel / stainless ## Dimensions & Specifications (ISO 1234 / DIN 94) | Nominal diameter (mm) | Hole dia min (mm) | Hole dia max (mm) | Common length range (mm) | Material | Reference standard | | --- | --- | --- | --- | --- | --- | | 0.6 | 0.7 | 0.9 | 6~16 | Low-carbon steel / stainless | ISO 1234 / DIN 94 | | 0.8 | 0.9 | 1.1 | 6~20 | Low-carbon steel / stainless | ISO 1234 / DIN 94 | | 1.0 | 1.1 | 1.3 | 8~25 | Low-carbon steel / stainless | ISO 1234 / DIN 94 | | 1.2 | 1.3 | 1.5 | 8~30 | Low-carbon steel / stainless | ISO 1234 / DIN 94 | | 1.6 | 1.7 | 1.9 | 10~40 | Low-carbon steel / stainless | ISO 1234 / DIN 94 | | 2.0 | 2.1 | 2.4 | 12~50 | Low-carbon steel / stainless | ISO 1234 / DIN 94 | | 2.5 | 2.7 | 3.0 | 14~63 | Low-carbon steel / stainless | ISO 1234 / DIN 94 | | 3.2 | 3.4 | 3.8 | 18~80 | Low-carbon steel / stainless | ISO 1234 / DIN 94 | | 4.0 | 4.3 | 4.8 | 22~100 | Low-carbon steel / stainless | ISO 1234 / DIN 94 | | 5.0 | 5.4 | 5.9 | 25~125 | Low-carbon steel / stainless | ISO 1234 / DIN 94 | | 6.3 | 6.7 | 7.4 | 32~160 | Low-carbon steel / stainless | ISO 1234 / DIN 94 | | 8.0 | 8.5 | 9.3 | 40~200 | Low-carbon steel / stainless | ISO 1234 / DIN 94 | | 10.0 | 10.6 | 11.5 | 50~250 | Low-carbon steel / stainless | ISO 1234 / DIN 94 | | 13.0 | 13.8 | 14.9 | 63~315 | Low-carbon steel / stainless | ISO 1234 / DIN 94 | Inside the plant ## Manufactured in our own plant This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided. 1. ![Wire rod feeding into a cold heading machine](https://engineeringhardware.com/wp-content/uploads/2026/08/09-wire-rod-feed-cold-heading-machine.webp) 01 **Cold heading** Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail. Head dimensions and under-head radius checked at set-up and per shift. 2. ![Thread rolling machine producing bolt threads](https://engineeringhardware.com/wp-content/uploads/2026/08/03-thread-rolling-machine-bolt-production.webp) 02 **Thread rolling** Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch. Go / no-go ring gauges to ISO 965 tolerance class 6g. 3. ![Baskets of bolts staged for heat treatment](https://engineeringhardware.com/wp-content/uploads/2026/08/05-heat-treatment-baskets-black-bolts.webp) 03 **Heat treatment** Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it. Core hardness and tensile tested per lot to ISO 898-1. 4. ![Zinc plated bolts in a treatment basket](https://engineeringhardware.com/wp-content/uploads/2026/08/23-zinc-plated-bolts-treatment-basket.webp) 04 **Surface treatment** Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list. Coating thickness and neutral salt spray hours to ISO 9227. ## Frequently Asked Questions ### Are Split Cotter Pins made to a recognized standard? Yes — they are manufactured to ISO 1234 / DIN 94, so dimensions are interchangeable between suppliers when you quote the standard on your order. ### What are Split Cotter Pins used for? Precise location and light shear duty between two parts. They are supplied to ISO 1234 / DIN 94. ### Which industries use Split Cotter Pins? They are commonly specified in maintenance & repair (mro), fabrication & metalwork and jigs & fixtures, among other sectors. ### How do I choose the right size of Split Cotter Pins? Select on nominal diameter and on the fit the assembly requires. This product is available from 0.6 mm to 13 mm; the full dimension table on this page lists each size. ### Can I get a quote for Split Cotter Pins in the size and material I need? Yes. Use the technical drawing and quote form on this page to set the size and options, then send the exact configuration to our team for pricing and lead time. ## Related Pages Product page: [Split Cotter Pins — specifications & sizes](https://engineeringhardware.com/fastener/split-cotter-pins/) ### Split Cotter Pins Specification Guides ### Related Fastener Applications