国修 Design Profile of the nut and bolt H Bolt D D H d=D 6 H=0.86603p; D2=d2=d-0.6495p; D1=d-1.0825p;d=d-1.2268p; d=Diameter of nut:D=Diameter of bolt. 29 圈上拼大人生 Thread Form2,3 ·Types of thread forms >UNC =Unified National Coarse(粗牙螺纹) >UNF =Unified National Fine(细牙螺纹) >UNEF Unified National Extra Fine >UNS Unified National Special >UNR Unified National Round (round root) 3029 Design Profile of the nut and bolt 30 Thread Form2,3 •Types of thread forms UNC = Unified National Coarse（粗牙螺纹） UNF = Unified National Fine（细牙螺纹） UNEF = Unified National Extra Fine UNS = Unified National Special UNR = Unified National Round (round root)