Keep a variety of heat-set insert sizes and installation tools on hand. The inserts install into a straight hole that has been drilled, printed, or molded into your plastic part. Heat inserts with a soldering iron (included in some assortments) to melt the plastic when installed. As the plastic cools, it solidifies around the knurls and ridges on the insert for excellent resistance to both torque and pull-out. Made from brass, they’re corrosion resistant, electrically conductive, and nonmagnetic.

Tapered inserts are easy to guide into a hole during installation. Use a drill bit to create a straight hole, then taper the top half.

Flanged inserts have a wider end than standard inserts, which gives them a larger load-bearing surface and makes them harder to pull out. The flange also gives you a larger contact area for soldering. When threading into the flanged side, these inserts prevent over-tightening, which can cause brittle plastic to crack.