Installing stainless steel screws 304 (A2) and 316 (A4) as always been more difficult due to the materials being connected having similar strengths.

As a result thread damage is common both during installation and when drawing the screw then re-inserting. The solution has always been to use a steel thread first.

The most common practice when combining stainless steel sheets would be to drill the metal first with the required stub bit, this is then followed by the installation of a screw the same size as required but usually a zinc plated or steel screw due to its strength it can create the required tap. This screws is then withdrawn and the required stainless steel screw inserted.

This is both time consuming and also risks corrosion, any small residue of steel left behind could lead to hidden corrosion. In addition if the screw is withdrawn then re-inserted the thread is prone to wear and quickly starts to depreciate.

BS Stainless supply Super screws these self tapping screws supplied in both 304 (A2) and 316 (A4) are three times as hard as a traditional stainless steel self tapping screw which removes the need to insert the steel screw thus saving significant time. This also removes the risk of contamination and if the screw needs to be withdrawn then re-inserted this can be done without any thread damage. All screws can be supplied with polyamide or EPDM washers. We can also supply Super screws in Duplex 318L for sea water resistant applications.