lightweight Posted March 7, 2013 Share Posted March 7, 2013 (edited) Does anyone know if the pitch on an American 3/8" brake union is different to an English one. I'm having a nightmare making brake lines up.... Edited March 7, 2013 by lightweight Typo Quote Link to comment Share on other sites More sharing options...
0 Pete Ashby Posted March 7, 2013 Share Posted March 7, 2013 Does anyone know if the pitch on an American 3/8" brake union is different to an English one. I'm having a nightmare making brake lines up.... I think you'll find it's an American fine pipe thread I can't remember the tpi or pitch but you should be able to get 3/8" union nuts and T fittings via the standard dealers for not a lot of money. Pete Quote Link to comment Share on other sites More sharing options...
0 Pete Ashby Posted March 7, 2013 Share Posted March 7, 2013 OK found my data book, the correct name for these threads is 'National Pipe Thread' and they are cut at a taper of 1/16" per 1 linear inch. A 3/8" NPT has a TPI of 18 and a pitch 0.05556" the pipe OD for 3/8 NPT is 0.675" Pete Quote Link to comment Share on other sites More sharing options...
0 Gordon_M Posted March 7, 2013 Share Posted March 7, 2013 Sizes, always sizes ... These threads are American and for once they are not silly. I vaguely remember that an NPT male plug has the same thread pitch as the PARALLEL UNF thread of the same size, so if you have a UNF tube connector, you can just bung a suitable NPT plug in it without wrecking the threads. I expect you could put a UNF parallel plug in an NPT female too. The thread form is different, different angle, mostly different threads per inch than UK stuff and definitely different from anything that says metric on it. I've managed to find all the US threaded components, parallel and tapered, that I've needed over the years. I reckon many of them are easier / more available than the older UK ones. Quote Link to comment Share on other sites More sharing options...
0 lightweight Posted March 7, 2013 Author Share Posted March 7, 2013 Thanks folks, I think I've traced what I need via a classic American car restorer - really nice guy by the way.... http://www.customvilleamerican.co.uk/ If you find yourself in a similar situation Quote Link to comment Share on other sites More sharing options...
Question
lightweight
Does anyone know if the pitch on an American 3/8" brake union is different to an English one. I'm having a nightmare making brake lines up....
Edited by lightweightTypo
Link to comment
Share on other sites
4 answers to this question
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.