Only a few manufacturers have succeeded in establishing their own manufacturing of bi-metal screws. It is a special discipline that requires great technical know-how to master. The result, on the other hand, is products of the highest quality that, with superior performance, make an efficient difference and save time in a construction project.
A bi-metal screw is a combination of two different types of steel - hardenable steel and austenitic stainless steel. Stainless steel is corrosion-resistant and ductile, but soft and therefore unsuitable for self-drilling screws for steel substrates. The idea behind the bi-metal screw was to combine a drilling tip and the first few threads in hardenable steel with a screw in stainless steel. The invention of the bi-metal screw was a breakthrough in the fastening industry because it succeeded in combining the best properties from two different worlds in one screw: the strength of the hardenable steel and the corrosion resistance of the stainless steel.
This made it possible to manufacture self-drilling and self-tapping screws that are both corrosion-resistant and strong enough to drill into steel. In one efficient operation, the bi-metal screw thus provides the ideal combination of fast installation and corrosion resistance.
At RED HORSE, we have our own modern bi-metal manufacturing with a high degree of automation that ensures high manufacturing output and consistent quality. Manufacturing of bi-metal screws involves four essential processes:
Welding of the stainless part and steel part
Cold forging of the screw's drilling tip and thread
Hardening of the steel part, i.e. drilling tip and first few threads