Heavy hex nuts produced according to different standards, such as DIN, BS, AS, JIS, ISO, ASTM, ANSI etc. Heavy hex nuts produced according to different standards, such as DIN, BS, AS, JIS, ISO, etc.Different classes or grades are available, from Class 4 to class 10, from grade 2 to grade 8.Different surface finish can be supplied, such as black, zinc plating, HDG, Dacromet, etc.