Hexagon Socket Countersunk Head Screws standard:GB,DIN7991,ISO,JIS,ANSI/ASME, ... material:carbon steel,alloy steel,s/s Specifications of Hexagon Socket Countersunk Head Screws1.standard:GB,DIN7991,ISO,JIS,ANSI/ASME ... us wt any inquiry about fastener , your kind inquiry shall receive high attention.Also welcom to drop by our home page ...