What is the standard thread for shower hoses?

[murrmac]

Greetings from the UK.

In Britain there are two different Standard pipe threads, BSP, which is a parallel thread, and BSPT which is a tapered thread.

The standard thread here for shower hose connections is 1/2" BSP.

I am only aware of one American standard for pipe threads, NPT, which is a tapered thread, but I would assume that the thread connecting the shower head to the hose would not be a tapered thread , since the seal is made by tightening on to a rubber washer instead of "thread to thread"

I would be much obliged if some kindly and knowledgeable member would clarify this point for me ...

 

[Plumguy]

The one you are refering to I have always called parallel threads, they need a washer for the seal such as a shower hose. But, thru the different industries there a lot of different threads.

 

[Sponsor]

 

[hj]

thread

What you are calling a "parallel" thread is called a straight thread here as opposed to the standard tapered pipe thread.

 

[Plumguy]

Exactly, funny how terminolgy differs throughout the country.Now some guys call hose threads "coarse".I guess it is just like codes, although I heard they are thinking about making codes national right across the board.

By the way, I just noticed Moderator under your'e name. Is that something new? If so, congrats!! From what I've read out here it is deserving!

Mr. HJ

 

[murrmac]

So the thread used for shower heads and hoses isn't a pipe thread at all but is an ANC (American National coarse) thread ? Just like in your nuts and bolts ?

Can anybody help me further and tell me if it is a 7/16" ANC (14 TPI) or a 1/2" ANC (13 TPI) ?

I do actually have a reason for wanting to know this

 

[Jimbo]

The thread situation is much more complicated than that. The most common thread we think of in plumbing is NPT ( American Standard Pipe Taper Thread). The hoses on hand-held showers are probably NPSC ( American Standard Straigh Coupling Thread) or possible NPSM ( American Standard Straight Mechanical Thread). Even more likely, they are just whatevet the Long Duc Duong Shower Head factory thinks will work. And, the shower arm probably is NPT.
Pipe threads: 1/2 and 3/4 are 14 TPI; 1" is 11TPI.

Hose is another whole ballgame. The common standard is NH ( National Hose Thread) but there are a gillion variations:

National
Standard :NH
Straight
Iron Pipe NPSH
New York
City FD: FDNY
New York
Corp: NYC
Pacific Coast: PCT
Chicago
Fire Dept: CFD
British
Standard: BSP

¾†Garden Hose Thread (GHT): 1.0625 ODM -11 ½†♦ 1 ½†Underwriters Playpipe (PPS): 2.1875-12 TPI





HOSE THREADS



Canadian Suction Hose Threads


Lafrance Mack King Seagrave American Marsh Pierre Thibault


Suction Hose Threads


American Lafrance Mack Truck Seagrave FWD Hale Fire Pump Waterous Ward Lafrance Maxim


Canadian Standard 21/2" Hose Threads



AMA Alberta Mutual Aid 2.990 8
BCT British Columbia 3.000 8
CSA Canadian Standards Assoc. Ontario 3.125 5
QST Province of Quebec Standard 3.031 7
WCT Western Canada Fire Underwriters 3.250 6
NST Nova Scotia Zone 1 3.234 5
QMT Quebec/Montreal Combination 3.031 7

 

[hj]

thread

If it were a bolt thread, which it is not, it would be .84 x 14tpi.