MKVI hub nut

Stephen Blakey · Posted: Wed Dec 13, 2017 12:27 pm Post subject: MKVI hub nut

Bit of a long shot

Does anyone know the thread profile of the MKVI hub nut? It looks like 3 5/8" 8TPI, but the threads seem to be truncated. Also, the late and early versions seem to use a different profile.

I had assumed it would be something like a Whitworth profile.

I've resigned myself to paying £18 for the drawing from the other lot, but they haven't got it.

I'm gonna have a go at taking an impression and doing a high-res scan, however all the samples I can find are corroded to a greater or lesser extent.

Expressions of positivity and moral support sought please.

Christopher Carnley · Posted: Wed Dec 13, 2017 1:34 pm Post subject:

Whitworth Form, 55 degrees. They truncated them all.

Stephen Blakey · Posted: Wed Dec 13, 2017 6:08 pm Post subject:

Thanks for that. Who's they?

The word on the street is that Sir Joseph Whitwood liked his thread tips to have a radius equal to 0.137329 times the thread pitch. The don't look to have such a radius but appearances can be deceptive.

Christopher Carnley · Posted: Wed Dec 13, 2017 6:21 pm Post subject:

1) Rolls-Royce, "they" machined "them" all. " Cincinnati machine tools".

2) WHITWORTH" and 0.137 x p will do nicely.

Rolls-Royce went their own way, it gets a closer fit, you see.