162 replies to this topic

[jn1702]

I need a tap to clean up the thread in the end of the crank( flywheel bolt) what thred size is it and where can I get one thanks

[Big_Adam]

What the cheese is with all the white space?

Anyway, if I remember the crank thread is a silly very old very odd standard. Think the few people who have one is Guessworks and he paid a sum for it.

I shall have to search!

[998dave]

What the cheese is with all the white space?

I dunno - but I can't edit it out!

[mike.]

£120: http://www.minisport...TOLITD6049.html

[Guess-Works.com]

Yeah, I have one somewhere, but bug**red if I know where....

But if you want one for keepsies, can get you one for considerably less than Minisport want for one... IIRC I paid about £50 notes for mine to be made, but was considerably cheaper than stripping down an engine and replacing the crank.

[*DJH*]

5/8 16uns i had one a while ago and old it

[Dan]

They will always cost a lot more than most taps do. I think most tool shops will charge between £80 and £110 for them at the moment but they're almost guaranteed to be a special order. I seem to remember it's 5/8 Unified Extra-Fine or something like that. Where did you get one made for £50.00 GuessWorks and how many decades ago was that?

Edited by Dan, 27 March 2009 - 03:40 PM.

[Dan]

Ah yes that's right, it's Unified Special (UNS) not UNEF. UNEF is 24 TPI at 5/8", that would be ridiculous.

[DaveRob]

A 'respected engine builder' in Leicester told me to use 5/8 UNF BUT 16 tpi ........ thats what he told me it was.... 5/8th unf is normally 18TPI

Rob

[Guess-Works.com]

Went to my local engineering shop, and asked them to get me one, quick ring to the supplier, 2 days later freshly cut tap in hand... was about 4 years ago...

[Guess-Works.com]

A 'respected engine builder' in Leicester told me to use 5/8 UNF BUT 16 tpi ........ thats what he told me it was.... 5/8th unf is normally 18TPI

Rob

That's exactly what a 5/8 16UNS is

If there was enough of a demand for them I'd get'em to run a few off, which would make them cheaper...

Edited by GuessWorks.co.uk, 27 March 2009 - 03:50 PM.

[DaveRob]

Id have one........... maybe the start of a list here...lol

Rob

[Nightrain]

The Exact size is 5/8" WF (Whitworth Fine)

[Dan]

That's exactly what a 5/8 16UNS is

Exactly, Unified thread forms all use the same angles and peak and valley shapes. UNF is a certain pitch, UNEF is another pitch and UNC is another pitch again but if you want something that doesn't fit into a standard pitch it's a special. That's what UNS means. It's not UNF specifically because it isn't the same pitch as UNF, it's UNS.

If there was enough of a demand for them I'd get'em to run a few off, which would make them cheaper

I'd be interested if you do.

The Exact size is 5/8" WF (Whitworth Fine)

No it isn't, Whitworth threads use a different peak and valley shape from Unified and a different angle. Whitworth is 60 degrees with a radius at both the peak and the valley, Unified is 55 degrees with a radius at the valley and the peak cut square (which is exactly the same as Metric). Is there such a thread as Whitworth Fine? There's BSF but I've never encountered BSWF and I deal in Whitworth quite a bit considering it's an obsolete threadform.

Edited by Dan, 27 March 2009 - 04:03 PM.

[GraemeC]

Never come across Whitworth Fine before - certainly not in any of my engineering guides. Whitworth is a coarse thread type under the British Standard family, BSW, BSF, BSCY, BSP, BSPT, BSB which have a 55 degree thread angle.
The UN range is the adopted American standard that uses a 60 degree thread angle.

It would be odd for the crank to be the only part of the car to use BS threads when the rest were UN (apart from odd small stuff that used BA).

(I was writing this as Dan posted!)

Edited by GraemeC, 27 March 2009 - 04:12 PM.