... Socket Countersunk Head Screws standard:GB,DIN7991,ISO,JIS,ANSI/ASME,B18.3 material:carbon steel,alloy steel,s/s Specifications of ... Socket Countersunk Head Screws1.standard:GB,DIN7991,ISO,JIS,ANSI/ASME,B18.32.material:carbon steel,alloy steel,stainless steel3.class:8 ... .8,10.9,12.9;ASME/2,54.surface:plain,black,zinc plated,hot dip galvanised ...