hex socket set screw 1.standard:DIN,BS,JIS,GB,ANSI ... black,hdg 4.rohs iso certificate hex socket set screw1.various kinds of hex socket set screw available.2.high quality ... competive price.3.material of hex socket set screw:stainless steel ,carbon steel,alloy steel,copper and so on.4.good surface ... be made with different standards ISO,GB,ANSI,BS and special spec according require.6.size:M2-M22