国上开我大修 Thread Profiles2 H -Crests 6 Flank 55 H -Roots- H=0.96p;h=0.64p;r=0.1373p 1.British Standard Whitworth(B.S.W.)thread 21 圈上拼我大修 47.5 H-113634p;h-0.6p;r-0.18083p 2.British Association(B.A.)thread 2221 Thread Profiles2 1. British Standard Whitworth(B.S.W.)thread 22 2. British Association (B.A.)thread