BSF hexHead, Stainless A2
BSF - Set Screws
All screws on this page are stainless steel A2
This thread (BSF) was used in british cars until 1950, then they changed to UNF. UNF then stayed until the seventies. After about 1975 new develpoments were made with the now standard 'M' (metric) thread.
For me it is amazing that the BSF thread is still needed and therefore produced - even in stainless steel.