Wire Thread Inserts

A wire thread insert is a coil of hardened stainless steel wire that screws into a tapped hole to give you a new, stronger internal thread. It's the part that goes into the hole after tapping — the fix for a stripped or worn thread in aluminium, cast iron or softer steel, and it's also used in new parts where a harder thread is needed than the parent material can provide on its own.

We stock BaerCoil inserts in metric (M4 to M30), UNC, UNF, BSP and BSF thread forms, in 1xD, 1.5xD, 2xD and 3xD lengths. Longer inserts give more thread engagement for higher-load joints; 1xD is the standard length for general repair work.

Cut the hole first with a helicoil tap sized to match the insert, or buy the tap, insert and installation tool together in a thread repair kit. Once installed, a heli coil gauge checks the finished thread is within tolerance.

All held in UK stock. Order before 4pm and it ships same day.