I am working on a 1928 AJS and one of the threads on the carb has foxed me. It may not be original as the PO many years ago made some parts for the carb. The thread appears to be the same as the internal thread in the petrol tap. Not the top and bottom ones but the fine thread of the part that bolts down on the cork seal.
Anyone got an idea it seems to be 26 tpi but is not cycle.?
Thanks
Internal thread on push pull petrol taps
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clive
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Internal thread on push pull petrol taps
clive
if it ain't broke don't fix
if it ain't broke don't fix
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Groily
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Re: Internal thread on push pull petrol taps
Could it perhaps be 1/8th BSP Clive? (That's 28 tpi, so a tad finer than BSC)
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clive
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Re: Internal thread on push pull petrol taps
Its nearer 9/16 and 26 tpi
clive
if it ain't broke don't fix
if it ain't broke don't fix
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Groily
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- Joined: Thu Jul 04, 2002 1:00 am
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Re: Internal thread on push pull petrol taps
Hmm. A conundrum.
BSB (Brass thread) is all 26 tpi and 55° - but 'near 9/16ths' isn't a standard diameter. Seems to jump from 1/4 to 3/8ths in the charts.
UNEF (Unified extra fine) has 9/16th - but at 24 tpi and it's American , as is NPTT - National Pipe Tapered Thread - which has its "1/16th" size with diameter 9/16th" x 27 tpi
A one-off I suppose or I'm missing something - but 'Why?' A PO doing some fettling would be unlikely to go a unique route, and can't see why the original manufacturer would either. But . . . 'mists of time' and all that.
BSB (Brass thread) is all 26 tpi and 55° - but 'near 9/16ths' isn't a standard diameter. Seems to jump from 1/4 to 3/8ths in the charts.
UNEF (Unified extra fine) has 9/16th - but at 24 tpi and it's American , as is NPTT - National Pipe Tapered Thread - which has its "1/16th" size with diameter 9/16th" x 27 tpi
A one-off I suppose or I'm missing something - but 'Why?' A PO doing some fettling would be unlikely to go a unique route, and can't see why the original manufacturer would either. But . . . 'mists of time' and all that.