Trouble with my nuts

[Basket case]

Back to my Bond MkD resto which has stalled for a year.

I'm stuck for a speedo nut and a nut for my wiper motor. They seem to be 34 tpi which is a very odd size.

Can anybody suggest where I can get a 3/16 x 34tpi and a 3/8 x 34tpi nut?

Thanks

[Bob Purton]

could it not be .75mm?

[Basket case]

Possibly, for the wiper motor I'm going to try a M8 x .75 nut from a guitar jack socket, but I'm stumped for the smaller one (speedo).
Would they have used metric in the 50's?

[DaveMiller]

Would they have used metric in the 50's?

Quite a few threads of the time, especially on instrumentation, were BA (British Association) threads.  Strangely enough (and "not a lot of people know that"), BA threads are metric!

The standard BA series, known as B1, B2, etc, does use a 0.75 mm pitch - but not in the diameters you quote, unfortunately!

[Big Al]

BA, the Brexit of threaded technology.

Metric fine? BA is used by instrument makers. Not so sure about a wiper motor, but they tend to use a fine pitch. thread on the spindle. If you were near you could have had a delve in my bits boxes.