Split Lock Washer

A split lock washer is a spring washer with a split and raised ends. It presses against a nut or bolt head to help resist loosening from vibration.

A split lock washer sits under a nut or bolt head and its split ends press against the joint to resist loosening from vibration. It is often matched with a bolt or nut of the same thread and a flat washer where the surface needs protection. The washer suits general engineering and machinery assembly, and it can be used with a spanner or wrench of the matching size.

Black oxide gives a dark finish for indoor use and light oil protection. Zinc plating gives mild corrosion protection for dry or indoor work. Hot-dip galvanising gives a thicker coating for outdoor use.

This kind of washer is often made in spring steel, stainless steel 304 or 316, or copper and bronze for electrical or marine work. Stainless steel 316 suits wet or salty sites. Copper and bronze suit conductivity and non-magnetic needs.

This is a general guide to checking this kind of part. It says nothing about any supplier's parts.

Ask for a certificate of conformance and a material certificate for the wire or strip. On receipt, check the split gap, the free height and the inside diameter against your order. Check the finish for bare patches or uneven coating.