nuts 1.Material: low carbon steel 2.size: 3/8' - 1" 3.Grade:2.5.8.Head Mark:"S" S 8 , S10, S181 ... ANSI B18.2.2 FOR UNC HEX NUTS : FINISHED :1)PLAIN2)ZINC PLATED CR ... standard hex nuts for many years, including standards of ISO, DIN, ANSI, BS, UNI, JIS, AS, GB, etc. Our main products ...