Insert Types

Our wire thread inserts are available from stock in either free running or screw locking types, which come in five standard lengths and in various pitches and thread types, including metric, UNF, UNC, and British Standard. We offer a range of materials, finishes, and coatings of inserts, and can also manufacture inserts in special lengths and pitches upon customer request.


Free Running Inserts

Our tried and true free running wire thread inserts are produced from Austenitic Stainless Steel wire, which is cold drawn (profiled) to form a diamond shaped wire. The wire is then helically coiled to produce wire thread inserts that provide a high performance, heat and corrosion resistant internal thread far stronger than parent materials such as aluminium and magnesium alloys.

Larger in diameter than the tapped hole, the insert is compressed during installation, which provides maximum surface contact between the flanks of the wire insert and the tapped threads. Once fitted, the action of radial pressure between their coils and the flanks of the tapped hole holds them in place securely.

The flexibility of our inserts enhances 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 that we also stock.


Screw Locking Inserts

Our screw locking inserts offer the security of prevailing locking torque alongside the benefits delivered by free running inserts, which makes them a valuable and reliable choice for use in applications that are subject to cyclic vibration or impact.

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 that 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, thereby 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, allowing for repeated assembly whilst retaining a measureable level of prevailing torque.

Note: It is recommended that only close fit plated, or lubricated bolts and screws, are used with screw locking inserts.