GB hex nut is widely used,Website:http://www.chinajinrui.net, mainly in the field of machinery and equipment, construction, automobile, railway and other industries. Nut mechanical property has grade 4, grade 6, grade 8 and grade 10. GB hex nut covers the dimensional requirments of metric series hex nut. The common standard of GB hex nut is GB6170/6175. It includes normal hex nut and heavy hex nut. The size from M3-M64 diameter. StandardGradeFinshGB6170/6175 hex nut4white zincyellow zinc  black oxideH.D.GDacromet...6810