Insert molding is the process of overmolding thermoplastic material around a preformed component (an insert) to create a finished part that incorporates multiple materials. The inserts are generally metal parts used to reinforce the mechanical properties of the plastic part. The metal inserts are placed into the mold to form the part.

A variety of components are manufactured with insert molding, such as electronic parts, medical equipment, housings, knobs, handles and dials, and are found in several industries, such as medical, automotive and consumer products. Product designers and engineers frequently turn to insert molding for improving part strength while trimming part weight and reducing assembly costs, production time and labor.

Here’s an example from Harris Corp. on how its engineers use insert molding from Proto Labs Inc.

 

Proto Labs Inc.
protolabs.com