Anyone know about npt threads? I thought npt are standard and only 1 type. I purchase one 1/8 male npt and one 1/8 female npt from 2 different sellers. They both said threads are npt. When I got them, they will only screw in 2 turns and get hard and won't turn by hand anymore. Even with a wrench it will barely turn 3 before it feel like I might damage the threads. So why would 2 npt fittings not fit? Are npt thread not standard and there are many type or what? On the male I can see it is tapered. But on the female I can't really tell but it looks like its parallels. Isnt npt tapered and not parallels? Seller lied or what. Did I get 1 fitting in bsp/m10? Damn wasted money on fittings that doesn't fit.
This is how far it will screw in.
This is how far it will screw in.