Thread Forming and Cutting Screws
Thread cutting screws and thread forming screws are both types of self tapping screws. They make their own paths in wood, steel and other materials. Give them a punched or drilled hole and, from there, their threads will cut their own reusable mating threads. But there are differences between these two tapping screws. Thread forming screws do not squeeze displaced material out of threads; instead, that material stays in the threads, creating a tight hold with zero tolerance. This contrasts with the threads on cutting screws, which displace material (shavings) up and out of the hole, resulting in less internal stress in the material, and requiring less torque when installing. Items vary by length, diameter, thread size, head type (pan, flat, hex, and so on), drive type (phillips, star, hex, slotted, torx and so on), head diameter, and number in a package, to name a few considerations. For more on screws, see our hex head cap screws, socket head cap screws, machine screws, and shoulder screws.