Fish Bolt

A fish bolt is a heavy bolt with an oval neck and a dome head, used to join fishplates on rail tracks. It holds the rails in alignment and takes shear and vibration.

A fish bolt joins fishplates to rail ends on a track joint. It often takes a nut and washer of the same thread and class and is set with a spanner or impact tool. An oval neck version sits in a matching hole to stop turning.

Hot-dipped galvanising gives a thick zinc coating for outdoor and wet conditions. Plain finish has no coating and is for dry or painted assemblies. PTFE coating reduces friction and eases removal after service.

Fish bolts are often made in steel, stainless steel 304 or 316, or brass. Stainless steel gives corrosion resistance for exposed locations. Steel grades provide high strength for track joints.

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 mill test certificate for the steel. Check the thread, the oval neck and the coating on receipt.