Crank shaft thread

[woodypup59]

What size is the screw thread in the crank to hold the flywheel on please.

[iain1967s]

5/8" x 16tpi Whitworth form

[Louis]

According to the Guessworks site, it is 5/8" 16 TPI

http://www.guess-works.com/Shop/Parts/d ... htm?id=494

[woodypup59]

Thanks - if anyone has one, can you confirm the o/d of the tap over the cutting edges.

[GraemeC]

[bwaminispeed]

So, that would make it a 16-16 tap????

[251 ENG]

Its 5/8 x 16tpi whit form .

It's a special non standard thread size

[iain1967s]

Easily confused with a 5/8-16 SAE tap (more common here in USA), but that has a 60° angle thread form, so will under-cut the 55° of the Whitworth form. Blue loctite is your friend if someone else has already used an SAE tap...

[OzOAP]

I have taps available in my facebook shop if anyone needs one.

[woodypup59]

Does that make it the same size as the bypass hose spigot in the head ?

[GraemeC]

Yes - both ends of the crank and the bypass spigot are all this thread.

[woodypup59]

Great - its worth buying one then.