Insert Types

WTI wire thread inserts are available from stock in two types and five standard lengths.

You can have any length, pitch or material

Special lengths, pitches and materials can be manufactured to meet individual customer requirements.


Free Running Inserts

Produced from Austenitic Stainless Steel wire, which is cold drawn (profiled) to form a diamond shaped wire. The wire is helically coiled to produce a wire thread insert. The finished insert provides a high performance, heat and corrosion resistant internal thread which is far stronger than parent materials such as Aluminium and Magnesium alloys. 

Larger in diameter than the tapped hole, it is compressed during installation providing maximum surface contact between the flanks of the wire insert and the tapped threads.

The flexibility of the Wire Thread Insert enhances the load bearing capacity by deflecting the residual forces into a helical, which is dispersed into the wall of the tapped hole.

They are easily installed using a range of manual or automatic tools. Once fitted the action of radial pressure between their coils and the flanks of the tapped hole holds them in place. 



Screw Locking Inserts

For applications subject to cyclic vibration or impact, screw locking (or prevailing torque) inserts are of particular value. WTI screw locking inserts offer the security of prevailing locking torque in addition to the benefits delivered by free running inserts.

This is achieved by the action of one or more polygonal grip coils positioned within the insert's length, which exert radial pressure on the male thread. Each grip coil consists of a number of tangential locking chords which protrude inside the minor diameter of the normal free running coils. As the male thread passes through these grip coils the locking flats are displaced, thus exerting radial pressure or prevailing locking torque on the male thread. On removal of the male thread, the locking coils relax to their original form permitting repeated assembly whilst retaining a measurable level of prevailing torque. Note: it is recommended that only close fit plated or lubricated bolts or screws are used with screw locking inserts.