Threaded inserts for wood and heat-set tips for plastic

How threaded inserts for wood work

A threaded insert is a short steel sleeve with a coarse external knurl on the outside and a machine thread inside. Drill a blind hole, drive the insert with a hex wrench until it sits flush, and the hole now takes a 1/4-20, 5/16-18 or 3/8-16 bolt as many times as you like: a reusable mounting point instead of a wood screw that strips a little more with every assembly. It is the right repair for a chair that wobbles, table legs that loosen, a bed rail that has been taken apart too often, and for any softwood, plywood or MDF board where a screw has stripped. No tap and no epoxy are needed; the knurl cuts its own seat.

Our inserts are zinc-plated carbon steel, a material that does not rust inside the furniture and shrugs off vibration, and the kits add what the hole needs next: matching bolts in two lengths, hex nuts or both, and the hex wrenches to drive them. The 191-piece kit covers ten sizes across three threads; the 120-piece 1/4-20 kit is sixty complete sets for a run of chairs, cabinets or speaker boxes. Applications run from woodworking jigs and knock-down furniture to attaching legs, brackets and hardware anywhere a project will be assembled more than once.

For plastic we make a different tool. Heat-set inserts melt into a 3D-printed boss, and the brass tips in our kit, M2 to M8 on a long adapter, fit a standard soldering iron so the insert goes in straight without the hot shaft touching the part.