A bi-metal screw combines the best of two worlds – hardenable carbon steel and austenitic stainless steel. The stainless part is ductile and very corrosion-resistant, but it is too soft to be used in self-drilling screws for steel. For this reason, we make bi-metal screws, where the drill point and the first few threads are made of hardenable steel, while the rest of the screw is pure stainless steel.

Manufacturing of Bi-metal

Manufacturing bi-metal screws of high, uniform quality is a very special discipline that requires great technical and practical know-how. In its simplest form, it can be boiled down to six manufacturing steps:

  1. Cold forging the head of the stainless part
  2. Welding together the stainless part and the carbon steel part
  3. Cold forming the drill point
  4. Threading the screw
  5. Hardening of the carbon steel part – the drill point and the first couple of threads
  6. Surface treatment

Our primary  Production activities