... .(1) Tooth profile 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 is ... , the tooth profile angle is 60°, taper is 1:16, internal and outer thread is taper, it is used widely in ...