NUT,BARREL NUT,CAP NUT 1.ISO,ANSI,JIS,DIN,BS& non-standard fastener ... .8 ,6.8,8.8,9.8.... NUT,BARREL NUT,CAP NUT A good non-standard fastenerS manufacturer for your better ... are always use C1022 ,The percent C element is 0.18%-0.23% ,is higher hardness than other.2.Fasteners' Head ...