26/05/2026
The vast majority of threaded holes are produced using cutting taps. Many of those threads could be produced using forming taps, which can provide multiple advantages. For ductile work materials, thread forming can provide 𝗯𝗲𝘁𝘁𝗲𝗿 𝘀𝗶𝘇𝗲 𝗰𝗼𝗻𝘁𝗿𝗼𝗹 and 𝘀𝘁𝗿𝗼𝗻𝗴𝗲𝗿 𝘁𝗵𝗿𝗲𝗮𝗱𝘀 while 𝗶𝗺𝗽𝗿𝗼𝘃𝗶𝗻𝗴 𝘁𝗼𝗼𝗹 𝗹𝗶𝗳𝗲 𝗮𝗻𝗱 𝗽𝗿𝗼𝗱𝘂𝗰𝘁𝗶𝘃𝗶𝘁𝘆.
Unlike thread cutting, no material is removed during thread forming. Rather, the process displaces the material to generate the thread form. Since the metal’s structure is cold worked along the thread profile, the threads produced are generally stronger and have a smooth, burnished surface finish.
Forming taps must be applied in materials that cold form well. This includes light metals and light metal alloys as well as steels and other materials with tensile strength to 1200 N/mm2 and hardness below about RC 35 – 40. Generally, materials that produce a continuous chip when drilling are good candidates for thread forming. This list is longer than you might think, and includes wrought and cast aluminum and aluminum alloys, copper, brass, stainless steels, carbon steels, and zinc diecasting alloys.
