Gauges

[katy]

Thanks.
According to Machinery's Handbook, 1/8" BSP is 28 TPI whereas (US) 1/8"NPT is 27 TPI.

[mike.perry]

Some photos of the dual gauge installation<br><br><br><br><br><br>

[jaekl]

Thanks.
According to Machinery's Handbook, 1/8" BSP is 28 TPI whereas (US) 1/8"NPT is 27 TPI.

That's right we Colonists just have to be difficult.

But back to my question, if Austin tooled the A series to be US threads, would they keep the British pipe threads? Gotta see if I can find a loose sending unit and put the gauge on it.

[PSL184]

I might just be me but I'm not following what you mean by "US threads". When the engine was designed the UK was on the, now known as, "old" imperial system. Metrication did not come into the UK until the 70's. Most nuts and bolts on the Minor are Whitworth "BSW" and pipe fittings (brakes, sender units etc) BSP which was standard stuff at the time....?

[bmcecosse]

The power units however - were UNF threads ! Becuase these use 'AF' spanners - some folks think the AF somehow refers to America! It doesn't. At the small 1/8" pipe size - the difference between 27 and 28 tpm (over the short length involved ) is not significant. But the correct fitting IS the 1/8" BSP.

[mike.perry]

If you fancy some bedtime reading go to Off Topic, The Standard Whitworth, Aug 7th, and trawl through the various references which cover just about every available thread

[jaekl]

Sorry, I was a bit assuming. That makes sense. Only the straight threads would be UNF and any pipe threads if required could be a local standard. Still strange that they choose pipe threads for the oil sending unit. (trying to get back on the subject)