Helical Thread Inserts are used primarily for reinforcing or repairing threads in aluminum, magnesium and plastics. This page summarizes where they fit, the industries that rely on them, and the practical points to get right when you specify them — to DIN 8140. Stocked across roughly M3 to M20, they cover general to heavy-duty work.
Typical Applications for Helical Thread Inserts
The most common settings where these are specified:
- Plastics & composites: reinforced, reusable threads in molded parts.
- Aerospace & motorsport: lightweight alloy parts needing full-strength steel threads.
- Field repair: recovering a stripped thread without scrapping the part.
- General machine building: fastening covers, brackets, motors and sub-assemblies on production equipment.
- Maintenance & repair (MRO): a stocked size for servicing existing plant where the original fastener spec must be matched.
How to Specify Helical Thread Inserts for Your Application
- Size: Match the nominal size to the mating thread or hole. This product spans M3–M20; check the full table below for the exact dimensions of each size.
- Tap & length: Drill and tap to the specified STI size, and pick insert length (commonly 1.5×D or 2×D) for the load and parent material strength.
- Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
- Standard: This product is supplied to DIN 8140. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.
Where Helical Thread Inserts Are Not the Right Choice
Not a fix for a hole that is already oversized beyond the STI tap range, and not needed in steel that already holds a thread well.