Whitworth Tools

Snap On Tools. They make all kinds of B/S Tools

Which country are you in?

Hmmm Location??? Yup I should have mentioned I am in the States on the east coast. I have found a bunch of good suppliers in the UK and Germany but the US has not been that easy. I have found a few dealers here but I would love to have a few more options\.

Thanks for your help,

Eric

Sorry, can't help. Plenty in OZ including Snap On. Our own tool manufacturer called Sidchrome was bought out by Stanley some years ago. Stanley still make Whitworth, better known as B (british) S (standard ) under the Sidchrome label.

Jim

Having turned a few Whitworth bolt on limey bikes in the past, I seem to remember using inch size wrenches. I think that Whitworth wrenches are sized according to the bolt diameter i.e. a 1/4 whitworth would be the same size as a 7/16" wrench...the actual headsize of a 1/4" bolt. The only other difference between the bolt/thread systems is that the whitwirth thread is a 50 degree threadform while American is 60 degree. This also explains why american bolt will screw into whitworth motorcycles. Not a perfect fit, and they require a bit more torque to run them in...they work in a pinch, especially useful due to limey bikes raining nuts and bolts when tooling down the road...hard to find a whitworth bolt in a hardware store 50 miles from home!

This may make some of you sick! I got my set of open end and box end Whitworth wrenches at Sears--in the middle 1960s. I later added some sockets.

Yes, they are sized by the bolt diameter, but I don't think the XF sizes are the same as US sizes--I sometimes try them (or metric) when I get a severely rusted US bolt, but this seldom works.

I got mine because I had a British car at one time. The Rolls-Royce Owners Club probably can recommend a present day source, but it is liable to be higher priced than alternates.

here is the whitworth thread form chart.

bolt dia ins, T.P.I, pitch of thread, thread core dia, hexagon AF, hexagon corners

1/4 - 20 - 0.050 - 0.186 - 0.445 - 0.51

5/16 - 18 - 0.0556 - 0.241 - 0.525 - 0.61

3/8 -16 - 0.0625 - 0.295 - 0.600 - 0.69

7/16 - 14 - 0.0714 - 0.346 - 0.710 - 0.82

1/2 - 12- 0.083 -0.393- 0.820- 0.95

9/16 - 12 - 0.083 - 0.456 - 0.920 - 1.06

5/8 - 11 - 0.091 - 0.509 - 1.01 - 1.17

3/4 - 10 - 0.100 - 0.622 - 1.20 - 1.39

7/8 - 9 - 0.111 - 0.733 -1.30 -1.50

1 - 8 - 0.125 - 0.840 - 1.48 - 1.71

1,1/8 - 7 -0.143- 0.924- 1.67- 1.93

1,1/4 - 7 - 0.143 -1.067- 1.86- 2.15

1,1/2 - 6- 0.167- 1.287- 2.22- 2.56

1,3/4 - 5 - 0.200 - 1.494 - 2.58 - 2.98

2 - 4,1/2 - 0.222 - 1.715 -2.76 - 3.19

I hope this helps you. It's not not quite the answer to your question but it will give you a bolt head size to convert to metric or any other size spanner.

( sorry about the dashes in the colums but it all got squashed up when i when't to submit it.)

There are two forms of Whitworth spanners. Those stamped W are for pre WW2 haed sizes and those stamped BS are British Standard Whitworth sizes introduced during WW2 to save steel (the heads are smaller). Some sizes can be tightened ok with Mertric and Inch A/F sizes some can't 5/16 is one such animal.

I was forced to buy some W and BSW spanners by a former employer and they are basically useless. Whitworth stuff in the hardware stores these days can have any head size and the parts bin may well have a mixture.

If you can only source Snap-on be prepared for some rounded nuts when you use open end spanners (from bitter experience). If you can source Sidchrome via the used (collector) market at reasonable prices you will be well pleased.

The screw sizes that I gave were from a reference book that I brought in the late 1960's when I was an apprentice.

But thank you for reminding me of the thread change that took place during the war.This new thread became the UNC thread. The thread pitch remained the same, The thread diameter remained the same but the tread angle changed to 60degrees the same as the metric system.

For some strange reason the spanner manufacturers did not change from calling the the UNC thread whitworth. and this is where the confusion comes from.

So you are really looking for UNC spanners, Which are smaller in size.

I do not have a bolt head size chart for UNC but i think that the older Haynes workshop manuals had a spanner comparison chart in them.

No it wasn't a thread change just the head sizes got shunted up a size for instance the old 7/16 became the new 1/2. BSW is still 55 deg thread form. Britain in the early stages of the war was in big trouble for metals, remember a huge lot of gear had to be abandoned at Dunkirk. Iron ore wasn't as readily available then as it is today.

Even in Australia there was thought to be very little Iron Ore and export wasn't approved until the 1960s. Can't think why, as the explorers such as Forrest in the 1900s recognised the vast amounts of Iron but didn't see how it could be exploited.

The unification of US threads is another story.

Ok so you have got me hook line and sinker, and I am all ears. so could you please tell me your story of the whitworth / UNC thread.

The only thing that springs to mind is the Rudge Whitworth motorcycle of the 1920's era.
If it is the same Whitworth?.

beware the 1/2 inch!! unc = 13 T.P.I. bsw = 12 T.P.I. otherwise yes the bolts will fit each others nuts. We had both British, European and American cars for the whole time before metrification. We also know that before I.S.O. metric, metric wasn't interchangable from one countries cars to another.