Imperial nuts

[Phil P]

Believe it or not imperial nuts and bolts are still manufactured in the UK in large quantities. There are plenty of stockists around who can supply them at sensible prices. We are spoiled here in the Black Country with a good stockist of UNF, UNC, BSF, BSW, BA. Metric fine, Metric course. In black, HT grades S,T as standard and higher grades to order in black, plated and stainless steel. Every type of washer imaginable. Nuts in black,plated, stainless and brass and on and on. Go to Willenhall Fasteners Ltd on 'tinternet' and you will find them. Brilliant place nice people. They're just 4 miles from Jones Springs Ltd the best place on earth for car, commercial and locomotive springs. They're on 'tinternet'. Itsa bostin plerce talive in the art of the Black Country. Yow con gerrenithin off the shelf or med. Engineerin is aloive un well. Dow yow believe wot them prats on the telly tell ya.

Phil

[pryantcc]

Well, I've been measuring.

The one and one-eigth AF socket is the best fit, and just to be sure, I measured 1.125 inches across the flats of the nut. The "bolt" seems to be 3/4 inch bar. Only the last 1/2 inch is threaded, but I counted 8 threads in that half inch, so there seem to be 16 threads per inch. So, do I need to spec anything other than one and one-eigth AF for the replacement nut?

Thanks folks,
Paul.

[tractorman]

When ordering bolts, you use the bolt's diameter (ie 3/4" or whatever) and not the head size (1 1/8" in your example). However, 3/4" 16tpi is a UNF size, so order a whatever-length 3/4" UNF bolt (not a setscrew, which is threaded for the full length) and you should get the right thing. I can't promise the head size will be 1 1/8", though think it will be (my S4 Minx had 3/4 UNF nuts on the rear hubs and needed a 1 1/8" socket, so it should be right).

I'm not suggesting you use this seller, but here's an example:

http://www.ebay.co.uk/itm/1-1-2-3-4-3-8 ... 460935cd28

From this search:

http://www.ebay.co.uk/sch/i.html?_trksi ... &_from=R40

[pryantcc]

OK, I've ordered some 3/4" nuts, hopefully they are right!

[pryantcc]

OK, I've ordered some 3/4" nuts, hopefully they are right!

The ebay crowd initially sent me the wrong nuts, but quickly sent out the right ones. So, Conclusion is that I did indeed need 3/4inch UNF nuts.

Thanks everyone for your help, I'm now a wiser man!

[classicalgreen]

never heard of AF threads.. I was taught AF simply meant 'across flats' and was a referral to old fashioned imperial sizing of spanners eg 1and 1/8th" being ideal for wheel bearing nuts.
common imperial threads were whitworth (55 degree thread and coarse )
BSF ( british standard fine ) fine threads same 55 degrees thread slope but more threads per inch. ( TPI)
acme ....single and multi threads ..used on fly press. lathes and your vice.
then smaller threads used in toys. instruments and jewellery etc and referred to by number these under heading of BSA. number from 1 to If i recall correctly 26. 1 being largest . 2 ba being most common.
been over 45 years since i was involved in cutting threads etc as an apprentice. sure most of the information is still out there.
unified threads were brought in around early '70's .. these like metric bolt threads having a flank angle of 60 degrees.
metric use 60 angle too.
if we take a bolt or nut along to an OLD engineering company often found in smaller industrial areas..we may find somebody still having a set of thread gauges. we can still buy both imperial and metric thread dies so cutting own ought not be an issue.

[jimmyybob]

When ordering bolts, you use the bolt's diameter (ie 3/4" or whatever) and not the head size (1 1/8" in your example). However, 3/4" 16tpi is a UNF size, so order a whatever-length 3/4" UNF bolt (not a setscrew, which is threaded for the full length) and you should get the right thing. I can't promise the head size will be 1 1/8", though think it will be (my S4 Minx had 3/4 UNF nuts on the rear hubs and needed a 1 1/8" socket, so it should be right).

I'm not suggesting you use this seller, but here's an example:

http://www.ebay.co.uk/itm/1-1-2-3-4-3-8 ... 460935cd28

From this search:

http://www.ebay.co.uk/sch/i.html?_trksi ... &_from=R40

Unless that is your buying stuff in BSP then its all just gobledegook.

[tractorman]

BSP is reasonably simple - it's the pipe bore that you measure, eg: a 1/2" pipe has a bore of 1/2" and thus you need 1/2" BSP fittings.

I'm reasonably sure "Unified" threads were here long before the 70's - my 1954 Fergy had UNC and UNF threads (as did they all from introduction in 1948) and used "AF" spanner sizes (however, Harry Ferguson even had special bolts made so that the heads fitted the "Ferguson Spanner" that had 11/16" and 1 1/16" ends!). OTOH, David Brown still used some BS sized parts into the 70's (and later?) and identified Unified stuff with a "U" in a circle so that fitters could find the correct spanners etc more quickly! For some reason, the drain plug for the hydraulic filter is BSP on my 60's and 70's machines!

ISO metric became common on UK built cars from the early 70's (Mk3 Cortina being the first one I came across) but metric bolts had been used for sometime on the continent (I seem to remember that Japanese metric bolts were slightly different at the time).

[jimmyybob]

You sound like my neighbour he collects tractors the latest being a grey 'n' gold.
Jap metric always used different size heads for some reason and usually flanged.