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2.5mm Stainless A4-70 G316 Split / Cotter Pin (PinØ 2.2mm) DIN 94

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Technical Specifications

Specs - Cotter Split Pin Stainless G316.pdf Imperial vs Metric Strength Chart.pdf

More Information
System of Measurement	Metric
Product	Cotter Split Pin
Size	M2.5 (2.5mm)
Corrosion Protection Level	Ultimate
Class Grade	A4-70 G316
Material	Stainless Steel
Length (l)	Select from the dropdown
Eye Diameter (c)	4.00 - 4.60mm
Pin Diameter (d1)	2.10 - 2.30mm
Hole Size to Suit	2.50mm
Prong Length (a)	1.30 - 2.50mm
Eye Length (b)	5.00mm
Closest size in imperial	3/32"
Standard Made To	DIN 94
Brand	Brighton Best
Alternative Brands	Hobson Engineering

Dimensional data is a guide only. Tolerance differences exist between brands and batches

Description

M2.5 (2.5mm) Cotter Split Pins are folded wire pins whose legs spread on installation to physically lock a castle nut or axle in place.

About Cotter Split Pins

Cotter Split Pins are folded wire pins with two legs that pass through a transverse hole in a bolt, axle or castle nut. Once installed, the legs are spread apart so the pin cannot back out, providing the mechanical retainer of last resort for safety-critical joints that vibration could otherwise loosen. Manufactured to DIN 94 in zinc-plated steel for general use or A4-70 G316 stainless for outdoor and marine environments.

Also known as

Split Pins · Cotter Pins · Cotter Split Pins · Linchpin Cotter Pins · Safety Pins (Metal)

Pairs with

Slotted Castle Nuts

Frequently Asked Questions

What is a Cotter Split Pin for?

A folded wire pin that passes through a hole and has its legs spread apart to lock something in place. Most commonly used on a castle nut on an axle bolt or a hitch pin.

The classic mechanical retainer: a bolt or pin has a transverse hole, the cotter passes through, the legs are bent outward 90 degrees and the pin physically cannot back out. Standard on axle nuts, agricultural hitch pins, trailer linkages, brake assemblies and any safety-critical joint where vibration could loosen a standard nut.

How do I install a cotter split pin?

Push through the hole until the looped head seats on the work, then bend one or both legs outward 90 degrees against the work face.

For a castle nut on an axle: bend both legs against the flat face of the nut so the pin cannot rotate or back out. For a plain pin: fold both legs around the pin shank in opposite directions. The bending tool can be needle-nose pliers, a hammer punch, or your fingers for the smaller sizes.

Can I reuse a cotter pin?

No. The metal work-hardens at the bend each time the legs are flexed and will snap off after one or two cycles.

Always fit a fresh pin on reassembly. Cotter pins are commodity items. The failure mode (legs snap, retainer fails) is dangerous on safety-critical joints like axles.

What hole size do I need?

Drill a 2.50mm hole for this cotter pin. Standard hole sizes per DIN 94.

Standard hole sizes per DIN 94. The cotter pin nominal is the wire diameter of one leg, not the assembled pair. A 3.2mm cotter fits cleanly into a 3.3 to 3.4mm hole.

What strength class is this?

Stainless A4-70 G316. Property class 70 (700 MPa minimum tensile).

See the head marking chart and full strength table on our site for the full conversion table.

What standard is this manufactured to?

Manufactured to DIN 94.

DIN 94 covers the standard split cotter pin in metric sizes. Stainless A4-70 G316 versions are dimensionally identical to the zinc-plated steel original. Choose by environment.

Where are cotter split pins typically used?

Slotted castle nuts on axles, agricultural three-point linkages, trailer pins, brake calliper pins, and any rotating-shaft retainer.

Wherever a bolt or pin sees rotational load and a separate retainer is needed to physically prevent loosening.

Material & Coating

Stainless A4-70 G316 Austenitic stainless steel. Property class 70 designates a minimum tensile strength of 700 MPa with a 0.2 percent proof stress of 450 MPa. Lightly magnetic in cold-worked form, which does not affect corrosion performance.

Grade selection A2-70 G304 is the general-purpose stainless grade for outdoor and most chemical environments. A4-70 G316 contains 2 to 3 percent molybdenum, giving substantially better resistance to chlorides; A4-70 G316 is the preferred grade for marine, coastal and pool environments.

Important Do not pair stainless fasteners with plain or galvanised steel components in wet service. The galvanic potential difference accelerates corrosion of the less-noble metal.

How to Measure

Length Cotter split pins are measured from the underside of the eye to the tip of the legs. The eye sits on top of the hole and the legs are folded back to lock. Use a length that allows enough leg past the hole to fold back without being so long it interferes with adjacent components.

Still not sure? See our step-by-step identification guide for help measuring your fastener.

Resources

Technical library PDFs

For full technical data including key product information, range and a CAD drawing, see our Technical PDFs library.

Measurement conversion calculators

Convert between metric and imperial sizes, gauge to mm, decimal to fraction and TPI to pitch with our measurement conversion calculators.

Pricing & Delivery

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Disclaimer

Technical data Researched and compiled from numerous industry sources for the sole purpose of providing basic information. All material is advisory only and its use by anyone is entirely voluntary. Reliance on it for any purpose by anyone is at the sole risk of that person, and Bolt and Nut Australia is not responsible for any loss, claim or damages arising therefrom. In developing this information, Bolt and Nut Australia has made a determined effort to present it accurately.

Measurements Sizes are taken from supplier catalogues or hand-measured and should be used as a guide. Minor variation between batches is normal. Stock is sourced from various suppliers, so differences may exist between batches in markings, appearance or finish.

Product Photos & PDF Data Sheets Represent the product type, not exact size. PDFs are a reference guide only. Specifications may change without notice.

If you see any problems with any of our specifications or you require additional information please contact us.

Delivery

Orders UNDER $30

Weigh less than 500grams

Exceptions: Tools, Kits, Bulky items = Sent as a parcel with tracking

Small orders that fit into the slot of your Letterbox are sent:

FREE with Aust Post Letter delivery with NO TRACKING and delivery between 4-12 business days

Select a Quicker delivery service

$7.00 Parcel Delivery 2-7 business days
From $12.00 Express Delivery 1-4 business days
From $14.00 StarTrack PREMIUM Express Delivery 1-3 business days

Click & Collect - Warehouse pickup

Unit 9, 93 Rivergate Place, Murarrie, QLD

Place your order online and we will have it ready within 2 hours. Call if required sooner
Pickup times between 8am - 4pm, Monday - Friday

Orders OVER $30

Weigh more than 500grams

Included is orders under $30 but weigh more than 500grams or wont fit in the slot of your letterbox

Including Large and Bulky heavy orders are sent:

FREE as a Parcel Delivery WITH TRACKING and delivery between 2-7 business days

Select an Express delivery service

From $12.00 Express Delivery 1-4 business days
From $14.00 StarTrack PREMIUM Express Delivery 1-3 business days

Click & Collect - Warehouse pickup

Unit 9, 93 Rivergate Place, Murarrie, QLD

Place your order online and we will have it ready within 2 hours. Call if required sooner
Pickup times between 8am - 4pm, Monday - Friday

All delivery dates are estimated and depend on stock availability, delivery location, service chosen, size of order, time of year, when order was placed e.g long weekends or sale periods.

Further delivery information can be found on our Delivery page

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Supplier Details

MPN	QPS16PM025012, 154312, M2.5X12SCP6, SPIA4M25X12, 154316, M2.5X16SCP6, SPIA4M25X16, QPS16PM025020, 154320, M2.5X20SCP6, SPIA4M25X20, QPS16PM025025, 154325, M2.5X25SCP6, SPIA4M25X25, 154332, M2.5X32SCP6, QPS16PM025040, 154340, M2.5X40SCP6, SPIA4M25X40
UPC	9350629028833, 662403847349, 662403847363, 9350629028840, 662403847387, 9350629028857, 662403847400, 662403847424, 9350629028864, 662403847448