BSP Male can be tapered thread BSPT (can seal on thread) or parallel BSPP (female always parallel)
NOTE: female hose swivel fittings will seal on either type with seat
* these are different thread forms
N.P.T.F. Description as above Used on U.S. equip
½" N.P.T.F. will jam if mated with BSP. N.P.T.F. has sharper thread form
JIC
UNF thread with 37° protruding seat on male fitting
UN-O-RING
UNF thread using O-Ring on male thread as seal