Helicoils - UNF

Helicoils, sometimes called recoils or thread repair inserts, are precision inserts that are most commonly used to repair damaged or worn threads. They can also be used to create strong new threads.

A Helicoil is essentially a free-running, stainless steel wire coil that is inserted into a hole with a thread that has been specially tapped to accept it. It is used to create a standard-sized, internal screw thread within the existing hole. Helicoils come in a range of different metric thread sizes.

Our helicoils are available as individual coil inserts or as a kit. The kits contain everything needed to install a Helicoil, including the inserts themselves, a drill bit and a tap, an inserting tool and a tang break off tool.

Please note that some of the larger sizes of helicoils do not come with a drill bit, this would need to be ordered separately. These sizes are for coil inserts above M12. Please check the description on the specific product pages for further details.

UNF stands for Unified National Fine. It is a common imperial thread type with more threads per axial distance than its UNC equivalent.

Unified thread types (UNF and UNC) were introduced at the beginning of World War 2 to enable the interchangeability of machinery manufacturing between the USA, Canada and Great Britain. Still commonly found on a vast array of old machines and vehicles in the UK, UNF and UNC threads continue to be the standard thread in the USA and Canada.