Thread-forming screws work on a different principle from conventional bolted joints. Instead of cutting a thread into the material, they form the internal thread themselves as they are driven in. This chip-free process creates a clean, efficient connection—an obvious advantage, especially in high-volume industrial assembly.

As the screw is driven in, the material in the pre-drilled pilot hole is plastically deformed. The pilot hole diameter is slightly smaller than the screw diameter, causing the material to be displaced in a controlled manner and forming a precise internal thread with minimal clearance. Depending on the terminology used, thread-forming screws are also referred to as flow-forming screws or thread-forming fasteners.

These screws require a sufficiently ductile material to work effectively. Materials such as steel, aluminum, and zinc die castings are particularly well suited because they allow the necessary plastic deformation. The pilot hole must also be precisely dimensioned, as the thread can only form completely and retain its shape if the specified dimensions are correct.

The thread-forming principle offers numerous practical advantages. By eliminating the need for an additional nut, space and material are saved, while no chips are produced and no subsequent cleaning is required. The resulting connection is highly resistant to loosening and well suited for automated assembly, making thread-forming screws an ideal solution for high-volume production.

Typical applications can be found in the automotive industry, electronics manufacturing, household appliances, and mechanical engineering. Wherever fasteners need to be installed quickly, reliably, and economically, thread-forming screws offer a technically compelling alternative.