American hydrant thread name

[BryanLoader]

Can anyone tell me the proper nasme for the thread on 1 1/2 and 2 1/2 hydrant and hose fittings. I am trying to crossover some US Hydrants here to accept British Instantaneous fittings and I need the name of the type of thread coming off the 2 1/2" outlet on the hydrant. In Canada, we used to call it FHT for fire hose thread. No one in this part of the world (Middle East) seems to have a clue about it. I appreciate any help
Thank you
Bryan

[BCmdepas3280]

They call it NST (National Standard Thread) but they also have a corser thread that is called bastard thread.

[TWEJFD]

Once you step out of fire dept. circles (where it is indeed referred to as NST), the official engineering designation is "NH" for National Hose. The 2 1/2" would be specified 2.5-7.5NH (2 1/2 nominal size, 7 1/2 threads per inch, National Hose thread form.) 1 1/2 would be 1.5-9NH, although it is common (at least around here) for 1 1/2 to be "Iron Pipe" instead of "National Standard". In this case, it would be designated 1.5-11.5NPSH. This will actually thread onto an equivalent size taper pipe thread (NPT).

[FlashOver12]

Originally posted by Ltmdepas3280
They call it NST (National Standard Thread) but they also have a corser thread that is called bastard thread.

hahahaha that hilarious, hahahaha, even if it is true, its still hilarious, lol