BSF and Whitworth “Across the flats ” sizes.

[old martParticipant @oldmart]

Some of the older Haynes manuals used to have a very useful scale of sizes showing the various spanner sizes along it.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, here's a photo of my 5/8 W-11/16 BS which is A Bedford No.RW2022 and it has a 11/16W-3/4BS on the other end. I've had this for 50 years, but don't use it much now, however didn't use the 5/8W end very often, except for only for holding, while using the other end. These were advertised in the 1964 Buck and Hickman catalogue. there are also two scans from the same catalogue and you can see King Dick also did this size (DDW2100). One thing about spanner sets, is they don't always include all the sizes that are available and normally contain the preferred sizes or the ones mostly used and if you need the others, you had to obtain them separately.

Regards Nick.

Edited By Nicholas Farr on 12/09/2020 22:14:31

[oldveloParticipant @oldvelo]

One size that defies the use of metric or AF substitute is 5/16 Whit Post war.

[Roger BestParticipant @rogerbest89007]

I have a considerable collection of spanners that may have taken four generations to collect. I have yet to give them a good sort even though they where in my shed for a decade. They have been washed recently to remove asbestos and rat excreta, and are now in my back lobby for us to trip over.

The old ones are clearly "steam spanners" very thick and suitable for brass or bronze fittings, rather rusty, however I have noticed that the tolerance across flats is pretty loose, such that couldn't find a good fit for my USA South Bend lathe tailstock locking nut. The best one was made by a mangle manufacturer.

Has anyone else noticed this or is it just a case that spanners where pretty crude in the day?

Ta, Rog

[HopperParticipant @hopper]

Several large handfuls of 11/16 BSF and 5/8 BSW spanners listed on Fleabay. They must have been common at one time.

[HopperParticipant @hopper]

Posted by Roger Best on 12/09/2020 22:47:21:

I have a considerable collection of spanners that may have taken four generations to collect. I have yet to give them a good sort even though they where in my shed for a decade. They have been washed recently to remove asbestos and rat excreta, and are now in my back lobby for us to trip over.

The old ones are clearly "steam spanners" very thick and suitable for brass or bronze fittings, rather rusty, however I have noticed that the tolerance across flats is pretty loose, such that couldn't find a good fit for my USA South Bend lathe tailstock locking nut. The best one was made by a mangle manufacturer.

Has anyone else noticed this or is it just a case that spanners where pretty crude in the day?

Ta, Rog

Sounds like perhaps you have been trying to use British BS sized spanners on the South Bend's American AF sized nuts? They are that little bit different to where some will fit but sloppily.

Otherwise, old spanners get their jaws sprung from heavy use over many years and will be slack fitting. Those old "steam spanners" probably got flogged within an inch of their life with sledgehammers more than once before.

[Roger BestParticipant @rogerbest89007]

yeah Hopper, some have a huge amount of bruising.

I think I shall have to do some measuring.

[Tim StevensParticipant @timstevens64731]

I have some difficulty with the notion that before WW2 all BSF bolts had the original BSW size heads. My view (based on evidence which is now in the loft) is that all BSF sizes have been the same since the beginning of BSF in about 1905, and were the 'next size down ' of the original Whitworth sizes. That is certainly the case on all the pre-war motorcycles and cars that have been through my (mainly grubby) hands. Except of course for foreign ones.

There is one Metric size which is within about 0.002" of a Whit/BSF size – 18mm = 3/8W, 7/16BSF. And as 18mm is not a 'popular' metric size, they do crop up in unworn condition at shows etc. And many cheapo 7/16 AF and 11mm will fit 3/16W, 1/4BSF.

And 19mm = 3/4 AF, within the tolerances of even well-made spanners.

Cheers, Tim

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Tim Stevens on 13/09/2020 18:10:51:

I have some difficulty with the notion that before WW2 all BSF bolts had the original BSW size heads.

.

As well you might, Tim

… any idea where such a notion originates ?

MichaelG.

Edited By Michael Gilligan on 13/09/2020 18:37:46

[Howard LewisParticipant @howardlewis46836]

Using conventional spanners on hardware for which they were not intended, (Such as A/F on BSW / BSF ) is inviting rounded corners and bruised / cut knuckles! As many will testify, slackening a fastener with already rounded corners, using the "correct" spanner can be very difficult, if not impossible.

In extremis, I have carefully filed the flats of a damaged fastener to accept a spanner of another type producing a closer fit. Effectively, this removes the rounded corners, but results in a hybrid with a thread of one form and the head size of a different thread form. But where needs must and all that!

The only "slack" fitting spanners or sockets which are safe to use on BSW/BSF, A/F and Metric hexagons are Metrinch or other flank drive tools.

These, as the description suggests, drive on the flanks of the flats and not on the corners. Sometimes they will slacken fasteners which have resisted all efforts using correctly sized spanners, and on fasteners with damaged corners..

They take some getting used to, since the fit seems to be very slack, but they do work, and are often my first (And therefore only ) choice for slackening or tightening a recalcitrant fastener.

The convention, of using the same size hexagon on a BSF fastener where then thread is one size different from the BSW dates from BS 28

The various BS ( 28, 190 and the later 1083 ) specify the equivalent hexagon sizes. The Britool catalogue 106, illustrates the change by references 5 and 6 on page 128 . The change came about as a means of saving material during WW2, when steel was in short supply.

Howard

[Mike PooleParticipant @mikepoole82104]

I remember an old machine in our machine shop still wore its “war finish” label to advise of non standard fasteners and a lower standard of finish.

Mike

[Bill PhinnParticipant @billphinn90025]

Since I've no first-hand experience of spanners and sockets made under a later Whitworth sizing standard than the one that prevailed at the time my pictured spanner [and other Whitworth spanners and sockets I own] was made, and therefore have no firm idea of how the current sizing works, would someone be good enough to tell me, just as an example, what the actual jaw openings [in metric or imperial] of the 5/8 and 11/16 spanners are likely to be in the following case.

Thank you.

[Michael GilliganParticipant @michaelgilligan61133]

Here's another good page for the references:

**LINK**

http://progress-is-fine.blogspot.com/2017/01/the-evolution-of-standard-wrench-sizes.html

… it's better than rivet-counting

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Bill Phinn on 13/09/2020 19:23:25:

Since I've no first-hand experience of spanners and sockets made under a later Whitworth sizing standard than the one that prevailed at the time my pictured spanner [and other Whitworth spanners and sockets I own] was made, and therefore have no firm idea of how the current sizing works, would someone be good enough to tell me, just as an example, what the actual jaw openings [in metric or imperial] of the 5/8 and 11/16 spanners are likely to be in the following case.

Thank you.

.

The current standard specifies jaw openings in millimetres, Bill

I can't access it at the moment, but will let you know the numbers later

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Gilligan on 13/09/2020 20:03:23:

Posted by Bill Phinn on 13/09/2020 19:23:25:

[…] would someone be good enough to tell me, just as an example, what the actual jaw openings [in metric or imperial] of the 5/8 and 11/16 spanners are likely to be […]

.

The current standard specifies jaw openings in millimetres, Bill

I can't access it at the moment, but will let you know the numbers later

MichaelG.

.

For thread diameter 5/8“ and small head: 25.73mm to 26.05mm

For thread diameter 11/16” and small head: 28.04mm to 28.39mm

MichaelG.

[Bill PhinnParticipant @billphinn90025]

Many thanks, Michael! Very useful.

[larry phelan 1Participant @larryphelan1]

Never heard of a17mm spanner fitting an M12 nut !

I live and learn.

[Anthony KnightsParticipant @anthonyknights16741]

Many years ago I bought a set of 12 metric open ended spanners with jaw sizes ranging from 6 to 32 mm. This thread has made me look at the ISO standard for metric hex head sizes. Out of the 24 different ends on my spanners, only 11 sizes match the standard, leaving 13 ends and 3 complete spanners redundant. It seems to be a strange "standard " to me.

My Whit/BSF spanners are double ended, and the large end of one matches the smaller end of the next size up. This means you always have a pair of spanners the same size (except for the smallest and biggest size of course). A couple of correctly sized sockets sorts that out.

[Nick WheelerParticipant @nickwheeler]

Posted by Anthony Knights on 15/09/2020 08:24:43:

Many years ago I bought a set of 12 metric open ended spanners with jaw sizes ranging from 6 to 32 mm. This thread has made me look at the ISO standard for metric hex head sizes. Out of the 24 different ends on my spanners, only 11 sizes match the standard, leaving 13 ends and 3 complete spanners redundant. It seems to be a strange "standard " to me.

There's more than one standard!

While I would expect M6/M8/M10 to be 10/13/17mm spanners, German and Japanese cars don't use them. And they're different to each other!

There are reduced head Metric too, a K-series Rover has a lot of M6 bolts with 8mm hexes

[Anthony KnightsParticipant @anthonyknights16741]

The only oddball size I have come across is some thin M8 lock nuts which need a 14mm spanner. Mind you, I gave up messing about inside cars over 10 years ago, so have missed out on the joys of many sized bolt heads.

I thought that ISO stood for INTERNATIONAL STANDARDS ORGANISATION or something to that effect.

Edited By Anthony Knights on 15/09/2020 09:51:12

[Andy PughParticipant @andypugh44463]

Posted by Anthony Knights on 15/09/2020 08:24:43:

Out of the 24 different ends on my spanners, only 11 sizes match the standard, leaving 13 ends and 3 complete spanners redundant. It seems to be a strange "standard " to me.

Better to have spanners and no bolts than bolts and no spanners, which was the situation that prompted me to ressurrect this thread.

(The observation that many new whitworth sets do not contain a spanner to fit the old 5/8* head at 1.10" jaw opening. Ironically you might well have a 28mm and that would fit nicely)

[Nick WheelerParticipant @nickwheeler]

Posted by Anthony Knights on 15/09/2020 09:47:27:

The only oddball size I have come across is some thin M8 lock nuts which need a 14mm spanner. Mind you, I gave up messing about inside cars over 10 years ago, so have missed out on the joys of many sized bolt heads.

I thought that ISO stood for INTERNATIONAL STANDARDS ORGANISATION or something to that effect.

It does. But it isn't the only one.

After all, we could have just stuck with the first universal standard….

[Howard LewisParticipant @howardlewis46836]

Although this thread started about Whitworth hardware, it look as if Metric wrenches are introducing confusion between Fastener sizes and Spanner jaw sizes..

A 6 mm nut usually is 10mm A/F, while 8 mm are usually 13 mm, so a 12 mm fastener would need a 17 mm Spanner.

But there are exceptions, for various reasons, such as available space. and to ensure that a kit only needs to contain one spanner of each size. I have seen thousands of M8 fasteners with heads 10mm A/F but the nuts are the standard 13mm A/F, and M6 with 8mm A/F heads with 10 MM A/F nuts, so a M12 fastener with a 17mm A/F head would not be unusual..

Since most setscrews and bolts are made by upsetting plain bar, producing an "undersize" head makes life easier, and saves money by using less material per fastener. 8.8 grade steel fasteners may be pence each, but in Nimonic, or other exotic materials, you are talking Pounds Sterling, each!.

Howard

[SillyOldDufferModerator @sillyoldduffer]

Posted by Anthony Knights on 15/09/2020 09:47:27:

I thought that ISO stood for INTERNATIONAL STANDARDS ORGANISATION or something to that effect.

…

Yes, but it only means Fasteners made to that standard have to meet ISO specifications and can be tested to confirm it. Fasteners are often made to other standards, including Whitworth, and to proprietary specifications.

Standards aren't the law anywhere in the world unless the law makes them so. Weights and Measures are required to be metric in most of the world, otherwise things are mostly free to do as they please.

No different in the past. Whitworth spanners don't fit BA hex heads.

I suppose we have to live with the nuisance. Just as hex heads started to become more rational, a huge number of different screw drives have sprouted. JIS, Torx, Phillips, Posidrive, Tri-wing, Hex, Frearson, Double Square, the list seems endless. It's very annoying. Clutch is my favourite – can't be undone!

Dave

[Anthony KnightsParticipant @anthonyknights16741]

Posted by S.O.D 15/09/2020

I suppose we have to live with the nuisance. Just as hex heads started to become more rational, a huge number of different screw drives have sprouted. JIS, Torx, Phillips, Posidrive, Tri-wing, Hex, Frearson, Double Square, the list seems endless. It's very annoying. Clutch is my favourite – can't be undone!

Don't get me started about them. Introduced mainly by car makers to make life difficult for people who didn't want to pay brain surgeon rates to have their car serviced at a main dealer. I have a box of splines, torx bits, star drives and numerous other "specials" which were bought to do a particular job and have never seen the light of day since.

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