圈上大学Multiple Threads Screw(多线螺纹 1=n *p,n-number of threads tanA=_ 圆上泽夫通大学 Direction of helical groove Screw in Right hand Left hand 11
11 l=n p, n—number of threads dm l tan Multiple Threads Screw（多线螺纹） Direction of helical groove
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 12
12 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