What kind of thread could this be?

Trying to make up a puller for a steering wheel (Land Rover) so it's imperial (it really is in this instance!) Can anyone tell me which imperial thread is frequently confused for 6mm metric? To be a bit clearer, I can't use my thread gauges in this instance because they're a bit too wide to probe the hole in question. But a 6mm threaded rod *will* go in nicely like it's a perfect fit - up to a point! After several turns, however, it binds up. So... what imperial bolt size & thread type would this most likely be? Something very close to 6mm metric but 25 TPI. AF? UNF? UNC? Any ideas?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 21 May 2016 15:10:06 +0000, Chris wrote:

1/4" 10TPI would be my guess (so UNC?)
Avpx
--
"But you read a lot of books, I'm thinking. Hard to have faith, ain't it,
when you've read too many books?"
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 5/21/2016 4:31 PM, The Nomad wrote:

Not 10 tpi surely? 1/4 Whitworth and UNC is 20 tpi, 1/4 BSF is 26.
M6 coarse is 1 mm pitch (so 25.4 tpi). So pretty close to BSF.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 21 May 2016 17:01:16 +0100, newshound wrote:

He must mean UN*F*C, I would guess. ;->
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The Nomad wrote:

May be 1/4" whitworth (20 TPI I think)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 22 May 2016 02:03:34 +1000, F Murtz wrote:

Perhaps I didn't make myself clear enough earlier. Whatever this thread is, it's very, very close to 25TPI. Like *VERY* close if not spot-on. This is because the 6mm rod that almost fitted is *very* close to 25TPI. Cheers.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 5/21/2016 5:15 PM, Chris wrote:

Then it is 1/4 BSF.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 5/21/2016 10:06 PM, newshound wrote:

Sorry, or 0 BA (havn't checked but do not doubt Chris's figures).
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Chris wrote:

Well BSF.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 22 May 2016 21:56:41 +1000, F Murtz wrote:

Why I triped 10TPI when the brain said 20 TPI (or did I mean 1T/mm?)
Oh well put it down to old age and lack of sleep ...
Avpx
--
The Ephebians made wine out of anything they could put in a bucket,
and ate anything that couldn't climb out of one.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Don't forget 0BA: 6mm OD, 25.38 TPI, pitch 1mm
--

Chris

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

What age is the Land Rover? Before metric, most UK car threads were unified. UNC for threads into ally - but for steel and nuts and bolts generally UNF.
6mm would be closest to 1/4" UNF/C. The spanner which fits that is 7/16th AF. The next size up in UNF/C is 5/16th. About 8mm.
Generally, in terms of thread pitch, UNC is closer to metric than UNF.
--
*Don't squat with your spurs on *

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 21 May 2016 15:10:06 +0000, Chris wrote:

Do you need a puller?
Leave the centre nut on a turn or two, and give the wheel a really good wiggle and a thump from behind and a wiggle and a thump from behind. It'll let go soon enough. When it does, you will WANT that centre nut still on - else you'll get a steering wheel in the face...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 21 May 2016 18:05:34 +0000, Adrian wrote:

Tried it already. The problem is the more modern LR steering wheels are very rubbery affairs and lack the rigidity necessary for such an approach to succeed. Anyway it's probably just as well it didn't work as I'd left off the centre nut! :-D
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 21 May 2016 18:17:43 +0000, Chris wrote:

There should still be a steel frame inside the wheel, albeit padded externally.
Try the same as you'd try for a stuck roadwheel. Loosen the nut, go for a drive.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 22 May 2016 12:58:40 +0000, Adrian wrote:

I don't doubt it, but the frame could be made of cast iron for all the good it will do to clump it when its smothered in rubber. If you can't transmit the shock to the splines thanks to all the rubber, there's not much you can do - other than use a puller.

Won't work for a steering wheel; different forces in play.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Chris a écrit :

1/4" Whitworth. I have a box of mixed 6mm and 1/4 Whitworth roofing bolts and nuts, they are quite hard to distinguish apart, without testing them.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 21 May 2016 19:54:42 +0100, Harry Bloomfield wrote:

Brilliant! Turns out to be 1/4" Whit fine at 26tpi to be precise; many thanks indeed.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 5/21/2016 9:40 PM, Chris wrote:

Never heard of Whitworth fine; British Standard Fine, on the other hand, is 26 tpi.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 21 May 2016 22:10:30 +0100, newshound wrote:

That's what I meant: BSF (AKA Whitworth fine) there's a Whitworth course as well, it seems. So many thread forms!!!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.