Tapping Copper? Why a Forming Tap Is Your Best Friend

Copper is notoriously tricky to machine. Its high ductility and tendency to “gum up” make traditional cutting taps a headache — long, stringy chips often clog flutes, leading to broken tools and ruined threads. Enter the forming tap (or extrusion tap), the ideal solution for copper threading.

Unlike cutting taps, forming taps displace material rather than removing it. This chip-free process is a game-changer for copper: no more chip evacuation issues, no risk of chip packing, and a dramatically lower chance of tool breakage. The result? Stronger threads. Because the grain structure of the copper is cold-worked and compressed during forming, the threads exhibit higher tensile strength and superior wear resistance compared to cut threads. For best results, ensure your drilled hole diameter is precise — forming taps are far less forgiving than cutting taps when it comes to pilot holes. Also, use a high-quality tapping fluid to reduce friction and extend tool life. If you’re threading copper, switching to a forming tap will boost efficiency, improve thread quality, and keep your shop running smoothly.