Tapered thread pipe fittings

For smaller pipe sizes, threaded fittings are more commonly used to create connections between pipes
and between pipes and equipment (including some instruments). A very common design of threaded
pipe fitting is the tapered pipe thread design. The intent of a tapered thread is to allow the pipe
and fitting to “wedge” together when engaged, creating a joint that is both mechanically rugged
and leak-free.
When male and female tapered pie threads are first engaged, they form a loose junction:

After tightening, however, the tapered profile of the threads acts to wedge both male and female
pieces tightly together as such: