+- Austinsevenfriends (https://www.austinsevenfriends.co.uk/forum)
+-- Forum: Austin Seven Friends Forum (https://www.austinsevenfriends.co.uk/forum/forumdisplay.php?fid=1)
+--- Forum: Forum chat... (https://www.austinsevenfriends.co.uk/forum/forumdisplay.php?fid=14)
+--- Thread: Schrader Valve caps (/showthread.php?tid=733)
Pages:
1
2
Schrader Valve caps - Ian Williams - 23-01-2018
Can anybody confirm what thread is used on the original Schrader valve caps, it seems to be a bit of an odd ball, either 24 or 25 tpi I think and .480" diameter???
RE: Schrader Valve caps - Dave Wheatley - 23-01-2018
A quick google throws this up
http://www.practicalmachinist.com/vb/general/thread-pitch-size-219531/
But doesn't tie in with .480" x24/25
RE: Schrader Valve caps - Alan - 23-01-2018
Valve stem thread is either 5V2 or 8V1
RE: Schrader Valve caps - Stuart Giles - 23-01-2018
Thread dimensions here: http://www.gewinde-normen.de/en/valve-thread.html
RE: Schrader Valve caps - williamsderbys - 23-01-2018
From memory (started work there in 1956..) It's .302-32
Tracy Tools probably got taps & Dies.
I have one of Schraders repair tools which might work for you.
e-mail if you would like to loan.
John W
RE: Schrader Valve caps - Ian Williams - 23-01-2018
Thanks for the responses, according to Stuarts link it would appear that I am looking for Vg 12. Tracy tools only list taps for the modern threads i.e .302-32, I am looking to cut threads for the original Vintage caps.
RE: Schrader Valve caps - David Cochrane - 23-01-2018
Having measured some original ones I have, they seem to be 15/32" x 26tpi. I haven't managed to find any taps or dies yet.
RE: Schrader Valve caps - Ritchie Wilson - 24-01-2018
Valve tools have a die and tap to cleanup the threads on the valve. If an old enough one was found it would have the appropriate die.
Some people collect this sort of stuff and could have the right one.
RE: Schrader Valve caps - Robert Leigh - 24-01-2018
(23-01-2018, 09:52 PM)David Cochrane Wrote: Having measured some original ones I have, they seem to be 15/32" x 26tpi. I haven't managed to find any taps or dies yet.Your details confirm what I suspected: it looks like a CEI thread (Cycle Engineers Institute). Even big sidecar lugs on old motorcycles are 26 tpi.
RE: Schrader Valve caps - Ken Morton - 24-01-2018
I can confirm that the valve tube from the inflatable tube is .307 inch OD & 32 tpi. The old type fluted cover over the complete valve & tube is 12 mm by 1 mm pitch.