These heavy duty thread repair inserts are a great heavy duty thread repair option. Unlike wire type inserts that require specific taps and prewinders, thinwall solid thread repair inserts are installed with standard drills and taps with no need of a prewinder. Simply drill out the old threads, tap the new threads, screw in the insert, and drive the "kees" in to lock it in place. Can be used in metals and plastic and they are removable.