I ordered an air fitting actually four of them in total,with a 10mm push fitting and a male half inch B S P metal screw end for to fit into a half inch threaded female pipe hole. The company sent me a ten mm push fitting with a half inch BSP threaded fitting on the other end. I keep getting a fitting with a ten mm push ok but the other end threaded is coming out at nineteen mm when half inch should be 12.5. The guy on the telephone tells me I am wrong. I asked him if I have a half inch threaded female internal pipe I can fit a male which is marked at half inch and is actually much closer to three quarters of an inch 19 mm in fact. I am dumb and dumbfounded that such a discrepancy exists simply put how can nineteen mm be a half inch which is 12.5 mm nominal??? Alistair
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I need an education outwith metric training , i've had so far
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Originally posted by Alistair Hosie View PostI ordered an air fitting actually four of them in total,with a 10mm push fitting and a male half inch B S P metal screw end for to fit into a half inch threaded female pipe hole. The company sent me a ten mm push fitting with a half inch BSP threaded fitting on the other end. I keep getting a fitting with a ten mm push ok but the other end threaded is coming out at nineteen mm when half inch should be 12.5. The guy on the telephone tells me I am wrong. I asked him if I have a half inch threaded female internal pipe I can fit a male which is marked at half inch and is actually much closer to three quarters of an inch 19 mm in fact. I am dumb and dumbfounded that such a discrepancy exists simply put how can nineteen mm be a half inch which is 12.5 mm nominal??? Alistair
Pipe threads, if I remember correctly are sized according to the bore of the pipe, not the thread itself.
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Steve is right.
Pipe is sized according to the bore. So half-inch pipe has an outside diameter greater than half an inch, the exact size depending on the wall thickness.
Tube is sized by outside diameter, so half inch tube has a narrower bore than half an inch.
Half an inch is exactly 12.7mm, by definition.
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Originally posted by Jaakko Fagerlund View PostAh, the stupidity of imperial markings, you got to witness it first hand
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Pipe threads aren't specified by the ID any longer as the ID changes with wall thickness.Metric pipe is no different as the stated size does not correspond to the actual dimensions of the pipe.
http://www.kellypipe.com/common-pipe...on-tables.html
If you want real confusion throw in JISI just need one more tool,just one!
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Metric and Imperial pipe, fittings and flanges etc. are interchangeable. The metric guys should do the math on that.The shortest distance between two points is a circle of infinite diameter.
Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/
Southwestern Ontario. Canada
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It's the difference between pipe and tube, a 1/2" pipe is one with a 1/2" hole, a 1/2" tube is the diameter of the tube, not the hole, so far anyway!, I'm sure there's an exception to every rule I know.
Probably hose or some obscure medical thing.
I used to go to a place called Hartlepool, we made steel for the 42" pipe mill, forever problems with cracking and slag inclusions, making really clean steel is hard.
Mark
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Originally posted by Sun God View PostIt sure do, otherwise doing internal flow calculations is a right pain in the bum.
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I suppose I have very stupidly ordered a half inch assuming it would fit into a female half inch fitting and with this method half inch is not half of 25.4 I e 12.7 but instead nigh on 19mm instead. I fail to see how half inch 12.7 can be 19mm three quarter nominal size as I thought. Tomorrow it will be back to recognizing, that a half inch is 12.7 ,once again sorry MY mistake . it is like arguing a Mile and a Kilometer are the same thing. AlistairPlease excuse my typing as I have a form of parkinsons disease
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Originally posted by wierdscience View PostPipe threads aren't specified by the ID any longer as the ID changes with wall thickness.Metric pipe is no different as the stated size does not correspond to the actual dimensions of the pipe.
http://www.kellypipe.com/common-pipe...on-tables.html
But tube and pipe mean the same in here, unlike in English.
http://www.commercemetals.com/tube-v...plain-english/
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Originally posted by MattiJ View PostLuckily in here most shops also tell the real dimensions in millimeters ie 1"/DN25 pipe is also marked as 33.7X4.0mm (OD X wall thickeness)
But tube and pipe mean the same in here, unlike in English.
http://www.commercemetals.com/tube-v...plain-english/I just need one more tool,just one!
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