... -head boltsStandard: GB37,DIN,JIS,ANSIGrade:Class 4.8, Class 6.8, Class 8.8, Class 10.9, Class 12.9Size ... (316)SizeM(8-10)*(16-100mm)GradeClass 4.8, Class 6.8, Class 8.8, Class 10.9, Class 12.9StandardGB37 ... screws,bolts,nuts,washer and relative hardwarePhotoes as following T type stainless steel screw