Forgefix multi purpose pozi screw csk st stainless steel forgefix pozi3525ss these forgefix multi purpose pozi screws with countersunk heads are made from a2 stainless steel they are ideal for use in and with many materials ideal for use in sanitary locations and in marine environments stainless steel does not corrode rust or stain with water as ordinary steel does but despite the name it is not fully stain proof most notably under low oxygen high salinity or poor circulation environm