... angle is 55°, taper 1:16Internal thread type: Rp, Rc, outer thread: RRp-R is used widely in ... Drawing a.(2) ISO228 is non-thread sealed pipe thread. Internal and outer thread is parallel, the tooth profile angel ... Drawing b.(3) ANSI B1.20.1 is thread sealed pipe thread, the tooth profile angle is 60°, taper ... different for NPT and ISO7/1. But the lead is same for thread 1/2 & 3/4, they can assembly ...