Split Cotter Pins 1.6–6.3mm Pack of 20 — A4 Marine 316

Why choose these A4 stainless split cotter pins

Split cotter pins — sometimes called split pins or hairpin cotter pins — are the traditional locking device for clevis pins, castle nuts, shafts, hinge pins and tow-pin assemblies. Made from A4 marine grade 316 stainless steel, these pins resist saltwater corrosion and chloride pitting, making them the right choice for boats, trailers, outdoor equipment and any exposed mechanical joint that needs to be removable.

Sizes available

27 sizes covering the full DIN 94 range, in diameters of 1.6mm, 2mm, 2.5mm, 3.2mm, 4mm, 5mm and 6.3mm and lengths from 16mm up to 63mm. Choose the diameter to suit your pin hole and a length that leaves enough tang to bend back cleanly after fitting.

Pack option

Each size is supplied in a pack of 20. Mix sizes across our Fasteners range in the same checkout to qualify for free UK delivery on orders over £20.

Typical uses

Securing clevis pins on rigging, trailer hitches and tractor linkages; locking castellated nuts on wheel hubs and steering knuckles; retaining shafts on pulleys and rollers; gate and stable-door hinge pins; agricultural and equestrian gear; restoration projects and machine builds where a corrosion-proof retaining pin is essential.

How to fit

Pass the pin through the cross-drilled hole until the head seats against the workpiece, then bend each leg outwards (typically one up over the shaft, one down) using pliers to lock the pin in place. To remove, straighten the legs and tap the pin back out — stainless tangs tolerate moderate re-use without snapping.

Delivery

Same-day dispatch on orders placed before 2pm — free UK delivery on orders over £20.