Okay, I'm new and you've probably discussed this a million times... Where do you get British Std Whitworth nuts and bolts? Does anyone sell complete sets for specific makes and models? I have a 66 BSA Victor Endro and would like to use new correct nuts and bolts. Thanks for your help. Steve
Victor: Yes, it gets discussed a lot.....but always interesting. You don't really want any BSW stuff, I think. That is for MGs and Jaguars and the like. Fasteners on our bikes were often colloquially called "Whitworth" because wrench sizes are the same. What they are actually is Cycle thread (CEI?), UNF, UNC etc., etc. It takes a little study, and some thread gauges and such.
British Fasteners, a board sponsor, is supposed to be real good. If you only need a few pieces, easy way is to order by part number.
Re: British Std Whitworth????#55516 07/10/072:59 am07/10/072:59 am
For your 66, I don't think the parts manual often helps with sizes and thread forms. Starting with the 69 parts books they spelled it out a little.
Here are some examples: Your primary case screws, these are cheesehead CEI 1/4" 26 TPI. (Cycle Engineers Institute 1/4 inch 26 threads per inch. Or the screws holding the carb top on- 2BA. (British Association size 2)
And inside engine, a headbolt might be 3/8 BSF, British standard fine I think. A head stud might be BSF on one end and BSC on the other. (British standard cycle)
69 and 70 bikes were beginning to have "Unified Fine" and "Unified Coarse" threads.
Here is some useful trivia you may not know: Those nice engine cover screws that everybody butchered with Phillips drivers.....they were never Phillips, but Pozidrive. If you buy any of them be sure and get a #3 Pozidrive tip and you won't booger them up. I found #3 Posidrive driver tip at my local True Value Hardware.
All of the above is more or less true.
Re: British Std Whitworth????#55518 07/10/0711:31 am07/10/0711:31 am
But still with Whitworth... I was browsing in Hursts in St Mary Bourne yesterday for a 5/16" BSW die (seemingly the only size they didn't have, sadly), when I wandered into a leaking corrugated iron shed FULL of BIG Imperial wrenches and reamers and morse tapers and, and, and. Some of them still had the original preservative on, unused and probably never will be used. And, all I could do is think of this once proud nation's industrial heritage rotting, unwanted, destined like the skilled engineers who actually built things, for the scrapheap. Good for the BritBiker who wants a couple of ring spanners to tighten up his rear axle bolts, bad for those old enough to remember. The whole Meriden thing came flooding back and gave me a fit of the blues.
mike Member #: 147 1960 T120 Bonneville 1999 H*%^a VFR 800 FI V4 Triton Project (still keeping me sane (Ha-Ha!))
Re: British Std Whitworth????#55523 07/16/074:33 am07/16/074:33 am
It would also be a good idea to get some British thread gauges; I know British Tools and Fasteners has them.
Most of your engine hardware will be CEI, 1/4" X 26 tpi and 5/16" X 26 tpi. Any 3/8" bolts are also 26 tpi., but I believe the only 3/8" bolts are cylinder head bolts, and you would probably want to replace those by BSA part number.
Some of the chassis hardware is Unified, which carries the same thread densities as SAE.
Seriously, could someone explain again using charts and graphs and diagrams/hand gestures? If it dosn't screw in easily with fingers, STOP!
Where's a good place to buy thread guages for British motorbikes? Surely, one can throw money at the problem!
"This is not work you want to do after a couple of beers." (RF Whatley) "have a fire extinquisher handy or be careful" (rmaffeo) 1968 Atlas 1998 Daytona 955i 1987 exMoD 110 Landy Packet of crisps and a gob stopper
Re: British Std Whitworth????#55528 08/09/076:05 pm08/09/076:05 pm
Originally posted by waspfarmer: Where's a good place to buy thread guages for British motorbikes?
No such thing - at least, I hope not and, if there is, it's someone trying to sell you something you don't need.
*A* thread gauge is a small piece of metal with a series of serrations along one edge and a number stamped on it. If it's just a number, it'll be the number of teeth per inch that the serrations match; if it's a decimal (e.g. '1.25' or '0.8'), it'll be a metric thread gauge and the number refers to the pitch (the distance between any two adjacent teeth).
Normally, thread gauges are gathered together on a pivot and inside a protective cover, like feeler gauges. The idea is, you try a series of 'em 'til one set of serrations fall exactly into the the dips on a bolt or nut thread; you then know the tpi (Imperial/Unified) or the pitch (metric).
You buy sets of thread gauges at an engineering supplier; at the same place, buy a decent micrometer and something like the Zeus book. This is because, once you know the tpi/pitch, you need the micrometer to measure the diameter of the shank; you then take both bits of information to the Zeus book and it'll tell you what thread you have.
A couple of caveats:-
1. Do look for a 27 tpi thread gauge. 27 tpi is 1/8" National Pipe thread, as used on BSA and Triumph oil pressure senders from '69. Before '69, certainly Triumph used 3/8" Cycle (26 tpi), and certain :rolleyes: people mix 1/8"NP up with 1/8"BSP (British Standard Pipe, 28 tpi). The thread length on oil pressure senders is so short that, ime, you cannot reliably interpolate 27tpi from 26 and 28tpi thread gauges, you need a 27tpi (or a 54tpi) one.
2. Imho, don't bother investing in thread gauges with a number higher than about 30 (40 max., except 54 ) or pitch smaller than about 0.7mm (0.5mm max.); this is because ime you simply can't see whether the serrations match a given thread. An example: 2BA, 3/16"BSF, 3/16"UNF (aka No.10UNF) and M5 all have similar shank o.d.; 2BA is 31.4tpi, 3/16"BSF and 3/16"UNF are 32 tpi and M5 is 0.8 pitch (31.8 tpi), yet an M5 bolt won't screw into a 2BA nut; I defy anyone to tell 'em apart with just thread gauge and micrometer. Imho, a much simpler system is marked resealable plastic bags with an appropriate nut and screw or bolt in each.
Re: British Std Whitworth????#55529 08/10/071:24 am08/10/071:24 am
Well, I guess since this thread is not on the "BSA" exclusive board, I should interject with ....at least my Norton heavy twins, in addition to CEI threads, it does in fact use BSF and BSW. Well..... now that I think of it even my BSA A-10 has BSW threads?
dynodave BSA 3 1961-1963 Ducati 3 1992-2002 Norton many 1951-1975 87 Serv-Equip 100HP MC brake dynamometer,
Re: British Std Whitworth????#55530 08/10/071:41 am08/10/071:41 am
Yes I think you are right. My Triumphs used ALMOST ALL CEI fasteners. There are two 5/16 22TP1 applications. One engine case bolt and 4 handlebar clamp bolts. I seem to remember my A10's had a lot more BSW fasteners. Right?
Bikes 1974 Commando 1985 Honda Nighthawk 650 1957 Thunderbird/T110 "Flying Tiger" Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: British Std Whitworth????#55531 08/10/0712:01 pm08/10/0712:01 pm
Originally posted by dynodave: Norton heavy twins, in addition to CEI threads, it does in fact use BSF and BSW.
Yep, particularly BSW - aiui, when British bike makers moved to Unified threads, Norton didn't use UNC (because of the possibility of confusion with earlier BSW-threaded parts?).
Originally posted by HawaiianTiger: My Triumphs used ALMOST ALL CEI fasteners. There are two 5/16 22TP1 applications. One engine case bolt and 4 handlebar clamp bolts.
As standard, your Triumph would've left Meriden with CEI threads into iron and steel (including bolts and screws into nuts) and BSF threads into aluminium alloy - 5/16" x 22tpi is BSF and, at 1/4", CEI and BSF have the same tpi.
That standard applied to components made in-house or by suppliers that could be influenced; otoh, components supplied by, for example, AMAL or Lucas generally used whatever threads the suppliers favoured (BA, Cycle, BSW, UNF and metric tmk).
Originally posted by dynodave: my BSA A-10 has BSW threads?
Originally posted by HawaiianTiger: I seem to remember my A10's had a lot more BSW fasteners.
Aiui, as BSA and Triumph were part of the same company, they both used the same engineering standards.
Originally posted by andrewinpopayan: BSW? maybe BSC.
Afaik, 'BSW' stood for the coarse British Standard thread form, while 'BSCY' stands for British Standard Cycle, so no 'BSC' (for British Standard Coarse?) because of the possiblity of confusion with the aforementioned BSCY.
Re: British Std Whitworth????#55534 08/11/071:39 am08/11/071:39 am
The set of thread gauges I got from British Tools and Fasteners has just about every thread density between 10 and 30 with very few gaps. The same set also includes metric gauges. Between those and my SAE thread gauges, I don't worry about classifying hardware anymore, I just measure.
Another little aside: Some models used handlebar controls made in Italy, so you may find some metric hardware there.
If you want a slightly easier time when identifying threads you need the aforementioned thread pitch gauges which cover all eventualities and you need a "Zeus Book" which contains all thread forms, Cycle CEI, BSF, BSW, BSP, UNF,UNC, BA and Metric and a few others, along with a wealth of other good stuff like tapping drill sizes. Ask at a good tool supplier or search Zeus book at a Net site. BSF threads in alloy are delicate , the later switch to UNC was a good thing . My old 69 Tbolt didnt make the change, but it is was an early in the year model. Cheers Pod
71 Devimead A65 750 56 Norbsa 68 Longstroke A65 Cagiva Raptor 650 MZ TS 250 The poster formerly known as Pod
Re: British Std Whitworth????#55536 08/11/078:40 am08/11/078:40 am
Another thing, theres not much Whitworth (Coarse) series threading on old Brits, BSF and Cycle evolved to finer thread series because of the need for Vibration resistance, an interesting anorakfact, BSP (Pipe thread ) and Whit share the same same thread pitch and form but BSP sizes are quoted by Pipe Inside Diameter. True Whit threads are very coarse lumpen generally low tolerance and "Roch" and only considered useful for low tolerance clumpen work like boiler plates and girders, a Whit thread is stronger than a BSF thread and will accept more torgue, but due to the quick thread slackens fast for a given rotation, no use on a rattly brit twin . Many Brit makers used a fine thread bolt BSF or Cycle with a reduced head to the next size down head size but still using whit head standards.
Saves a lot of weight. True Whit is generally seen in big scale Power industry applications.
Poor Mr WHitworth, his name causes such confusion.
I have free access to mountains of Whit bolts and nuts,at work we have lots of 50s -60s heavy plant. None of it fits my BSAs,, although I have seen some 7/16 Whit used on Nortons, one tapped hole in a featherbed frame and some tin ware.
BSF( engine fasteners), Cycle( Headstock and various oddities), BA( Control levers, twist grip, carbs,electrics) , BSP (Fuel tap/tank.
The weirdest threads on your bike are the cotter pin nut ( 1/64" bigger than a 1/4 nut , a very weird Cycle thread only used for this application). The LHS footrest mount nut is a left hand thread.
Sorry about the long post but its a big topic. Pod
71 Devimead A65 750 56 Norbsa 68 Longstroke A65 Cagiva Raptor 650 MZ TS 250 The poster formerly known as Pod
Re: British Std Whitworth????#55537 08/12/0712:00 am08/12/0712:00 am
Originally posted by pod: an interesting anorakfact, BSP (Pipe thread ) and Whit share the same same thread pitch and form but BSP sizes are quoted by Pipe Inside Diameter.
Sadly, AIA that'd be wrong. E.g. ime, the BSP threads you're most likely to find on a Brit. bike are 1/8" and 1/4"; 1/8"BSP is 28tpi and 0.383" o.d. while 3/8"BSW is 16 tpi and 0.375" o.d. (or 3/8"BSF is 20 tpi), 1/4"BSP is 19tpi and 0.656" o.d. while 1/2"BSW is 12 tpi and 0.5" o.d. (or 1/2"BSF is 16 tpi).
Originally posted by pod: BA( Control levers, twist grip, carbs,
Actually, ime, AMAL barely seemed to have used the same threadform more than once! While carb. tops and float bowls are secured with 2BA screws, drain plugs are 3/8" Cycle and adjusters are machine thread (40 tpi). On the twistgrip, while the adjuster screws are 2BA, the 'bar clamp screws are 7/32"BSF. :rolleyes: