Serrated Safety Locking Washers M3–M16 — A2 DIN 6798A

Why choose these serrated safety locking washers

Type S serrated lock washers are a simple, reliable way to stop nuts and bolts working loose under vibration. The conical disc carries sharp external teeth that bite into both the joint face and the underside of the fixing head — creating a positive mechanical lock without the need for adhesives or nylon inserts. Pressed from A2 stainless steel, they hold up to damp interior, workshop and light marine conditions without rusting.

Sizes available

Stocked across the full common metric range — M3, M4, M5, M6, M8, M10, M12 and M16 — to suit machine screws, hex bolts and nuts to DIN 6798A specification. Pair with matching A2 hex nuts, dome nuts or cap screws for a colour-consistent stainless assembly.

Pack options

Available in packs of 10 or 20 per size. Mix sizes across the Fasteners range in a single checkout to qualify for free UK delivery on orders over £20.

Typical uses

Electrical equipment and panel work, machinery guarding, automotive and motorcycle fittings, brackets and frame fixings, garden and outdoor furniture, signage, marine fit-outs above the waterline, and any threaded joint subject to vibration where a serrated bite is preferred over a spring washer.

How to fit

Place the serrated washer between the nut (or bolt head) and the joint surface with the teeth facing the workpiece. Tighten the fixing to the recommended torque — the teeth will deform slightly into both faces, locking the assembly. Re-use is not recommended once the teeth have been compressed.

Delivery

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