1place of origin:Guangdong China(mainland) 2material:carbon steel,stainless steel,high strength alloy 3size:M2-M24 hex.socket screw1material:carbon steel,stainless steel,high strength alloy23size:M2-M24 ,length:10mm-120mm3finish:black oxide,zinc plate,plain finish4certificate:ISO 9001 2008, RHOS, hex.socket screw