Materials Components Finishes & Marking    

Helical Inserts

Examples:

Helical inserts are inserts made of coiled wire with a diamond-shaped cross-section. They screw into a threaded hole to form a mating internal thread for a screw or stud.

Because of this, helical inserts are the ideal option for creating high-strength threads in soft alloys like aluminum in CNC machined or CNC turned parts.

Helical inserts are also commonly known as screw thread inserts (STIs), or their Stanley Engineering Fastening brand name Heli-Coil®.

Tang vs Tangless Helical Inserts

Helical inserts are either tang-less or contain a tang, which is a small piece of metal that's used to apply the torque required to insert the helical insert.

Protocase stocks a variety of tanged helical inserts. Tangless options can be ordered for additional leadtime and cost.

Free Running vs Self-Locking Helical Inserts

Free running helical inserts have a thread that is smooth and free running.

Locking helical inserts have the same characteristics as free running, but also allow frequent removal and reassembly of screws without appreciable loss of torque and positively secure threaded members against vibration or shock loosening.

Stocked Helical Inserts

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