Heat-Set Insert

A heat-set insert is a threaded metal insert installed into plastic with heat. The insert melts into the plastic as it is pressed in, and the plastic resets around it to lock it in place.

A heat-set insert is pressed into a drilled hole in plastic with a soldering iron or similar heated tool. Heat softens the plastic so the insert sinks in and grips when the plastic cools. It takes a machine screw of the same thread.

This insert is often made in brass for good heat transfer and corrosion resistance. It can also be made in stainless steel or steel where a different strength or magnetic property is needed.

This is a general guide to checking this kind of part. It says nothing about any supplier's parts.

Ask for a certificate of conformance covering material and thread. Check on receipt that the insert is clean, the thread is undamaged, and that it seats squarely in a test hole without cracking the plastic.