(常用的是德标和美标)GB (国标)ISO(国际标准)DIN (德制) JIS (日标)ANSI /ASME (American National Standards Institute – ANSI;American Society Of Mechanical Engineers – ASME)(美标)BS (英制) IFI =Industrial Fastener Institute是美国工业紧固件协会的标准 BA (英制)