... head threaded stud bolts1) Material: High quality carbon steel Class :4.8, 5.8, 6.8, GR ... 8,A325-1,A490-1 ,GR.B7,GR.B7M3) Material :stainless steel :302 ,304 ,305 ,316, 304L ,316L ,410, ... ,Black galvanization ,Steam Black ,Ash phosphorus ,Brass , Nickel plate ,Chrome plate ,Heating galvanization ,Zinc plated(yellow, black, green)Packing: ... box. 3)As to customers' requirement stainless steel stud screw