圆上泽文大学 Identification Codes Two major types of identification codes >English units(英制) >Metric units.(公制) Most fasteners used in the United States, Canada and the United Kingdom is known as >Unified Inch Profile >According to ANSI standards ANSI B1.1-1982. Europe uses ISO International Organization for Standardization). 圆上清支大华 Thread Standards ▣American National(Unified,.UN)standard(英制) >UNC:Unified National Coarse(粗牙螺纹) >UNF:Unified National Fine(细牙螺纹) >UNR:Unified National Round(round root) >UNEF:Unified National Extra Fine >UNS:Unified National Special ▣Metric standard(米制) >MC: >MF >MJ:round root 1212 Identification Codes  Two major types of identification codes English units（英制）  Metric units.（公制）  Most fasteners used in the United States, Canada and the United Kingdom is known as Unified Inch Profile According to ANSI standards ANSI B1.1-1982.  Europe uses ISO ( International Organization for Standardization) .  American National (Unified, UN) standard (英制) UNC: Unified National Coarse（粗牙螺纹） UNF: Unified National Fine（细牙螺纹） UNR: Unified National Round (round root) UNEF: Unified National Extra Fine UNS: Unified National Special Thread Standards  Metric standard （米制）  MC:  MF  MJ: round root