Another Norton Newbie question!

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Nov 23, 2004
Ok OK OK...I know your getting sick of my posts...But where can I get screws, nuts,bolts...ect???? :?
You can buy your hardware at any local supplier in town . A lot can be bought right at a Home Depot . For bearings and oil seals look up someone in the phone book that sells this stuff . The guy selling the bearings will most like sell the seals also. The price will be about 1/3 the cost of buying from a Norton Supplier. Don't just buy one . Get yourself a nice stock of consumable items. ( seals , hardware , gaskets . kick starter pawl ) just to name a few
Are all the fasteners SAE? I thought they were in between metric and SAE.....I.E Whitworth?

Not exactly "in between" but you will find various types of threads used on Commandos = Whitworth(BSW)-BSF-BA-UNF-BSP-metric etc.

Bolts that fit to nuts or screw into steel parts are generally UNF.

Bolts that screw into alloy are NORMALLY Whitworth, although the screws holding the head steady to the head are BSF for example.

Care has to be taken as a large number of Whitworth and UNC thread pitches are the same although the thread forms are different (also hex sizes are different) so it's possible to screw a UNC bolt into a Whitworth thread but it isn't considered to be good practice.

Amal carb screws are normally BA, also some electrical component screws.

So it's really a case of check as you go as you never know what has been changed by previous owners!

Thread pitch gauges take a lot of the guesswork out of thread identification, and if you want to know what any particular thread is (or should be!) on anything then just ask on the forum.
There are plenty of thread charts on the web to help identify thread types.

Here's one that should give all the info you need:
>Screw Threads.
Triple John,

On a Commando you will find that chassis fasteners are SAE, either UNC thread (when threaded into aluminum) or UNF when fitted with a nut or tapped into steel. The engine and gearbox fasteners are usually 26TPI or Cycle thread (CEI) for fasteners from 1/4 to 7/16 and 20TPI for 1/2 to 5/8. Small screws may be BA thread. These are all commonly misnamed Whitworth thread.

The engine and gearbox fasteners are available from most Norton parts suppliers or in stainless from Stan Smith at Rocky Point Cycle. and others.
chassis fasteners are SAE, either UNC thread (when threaded into aluminum)

Coarse threads on a Commando are, or should be BSW (Whitworth) not UNC even though the thread pitches are mostly the same as far as I am aware?
Geez...Now I'm really confued! So there are three or four different types of threads used! :x I'm used to Japanese bikes where everthing is metric! Is there a local supplier in Chicago that can supply various fasteners....I have several misc screws missing throughout the bike....and I hate to pay $4.00 shipping for a couple screws.
So there are three or four different types of threads used!

More like seven or eight!

But if you identify which bolts you need I'm sure we could tell you what they should be, if you could give the part numbers that would help.
Triple John,
As you have seen from the various postings British screw fasteners almost fall into the realm of 'lost wisdom of the ancient's'. In my opinion you would be better off paying the $4 shipping rather than run the risk of damaging a valuable bike. Why not consider ordering a parts manual for your bike and replace a number of the more obvious screws (like timing cover for example - there are nice stainless BSW Allen heads available for these) this would at least maximise the benefit of a minimum charge for posting.


"Coarse threads on a Commando are, or should be BSW (Whitworth) not UNC even though the thread pitches are mostly the same as far as I am aware?"

You might be correct, but it usually doesn't matter as the TPI are the same except for the 1/2 inch size. The thread angle is 55 degrees for BSC (BSW) and 60 for UNC but they will thread easily. I suspected that all the fittings were SAE as the foot peg mount studs are coarse thread into the aluminum Z plate and fine thread with nuts on the peg end. It seems that if they would thread one end with UNF they would use UNC for the other, not BSW.
I was thinking of going through the parts manual and ordering several different different size screws just to keep on hand....Is there someone that sells a fastener kit ?
Ron L,

I've checked through the Commando parts list pdf on the Norvil website, a large number of the fasteners are marked with the thread type and yes you could be correct about some studs being UNC thread!

The front crankcase to barrel stud (06-2639) is marked as UNF/UNC but that was about all I could find (apart from a bolt 14-1401 that I haven't been able to place yet) and the electric starter mounting screws on 850 Mk3 are also UNC, probably because the Prestolite starter was manufactured in the USA, but that certainly shows there could well be others so I stand corrected about ALL coarse threads being Whitworth!

You might be correct, but it usually doesn't matter as the TPI are the same except for the 1/2 inch size. The thread angle is 55 degrees for BSC (BSW) and 60 for UNC but they will thread easily.

Possibly in the US where there isn't the availability of BSW fasteners then I suppose it's an alternative but fitting mismatched threaded components together seems a bit of a poor option to me personally! >Download Our Catalogue.



Ordinary or stainless steel kits (or most single bolts/screws/studs) are certainly available from specialist Norton parts suppliers in the UK like Norvil, Hemmings, RGM etc.

And also available from specialist fastener suppliers like Molnar, D Middleton and others that specialise in stainless steel fasteners if you like stainless but you may have to order by size and thread type?.

There is a parts book for Commandos on the web here:>Norton.

So there's no reason why you shouldn't be able to find the part numbers and just get what you need?
And if you have the part number for the fastener, you can look it up on the Domiracer website and their description includes the length, diameter, and threads per inch.
Hello All,

I found a catalogue company here in Chicago called Metric Multistandard. They sell BSW, BSF, and BA...ECT in stainless and high tensile steel. They also have stores in Dallas, New York, Atlanta, Reno, and Germany. Here is a link to their website:

Best regards, John
An interesting company and website! They seem to carry British tools and taps, but the fasteners listed are mostly real Whitworth thread pattern. The fasteners found on Nortons are mostly CEI, which is 26 TPI. Be careful before you order!

What type of wrench fits a CEI fastener - SAE or Whitworth? Also, you mentioned that CEI is a "cycle thread." Presumably the "C" stands for cycle, what do the E and I stand for? Also, are CEI fasteners used on anything besides motorcycles? Why was CEI stuff developed? Am I asking too many questions?

CEI = Cycle Engineers Institute.

These threads were originally developed for use on bicycles.

Later known as BSC.

broken link removed

There aren't that many cycle threads on Commandos and most cycle fasteners have Whitworth hexagons I think.

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Hey All,

OK this gets more confusing every time I CEI? Jeez how are you supposed to match up fasteners when there are 6-7 different types on these bikes, If you don't have thread gauges for all the differnet types. The parts manual does not identify which type of thread and pitch just a part number.....

As I have mentioned previously if you download the pdf list from the Norvil website that should give the thread types of most fasteners.

>Download Our Catalogue>NorvilBySection2005pdf.
"Cycle" threads are an abomination. While at N-V, I tried very hard to get all fasteners standardized to US threads, or at least all UNF and UNC, but without success. To a large extent, that was blocked by suppliers who used the other standards. All too often we heard the argument "you're such a small account, why would we change?" That was very much the case with Lucas.

Cycle threads are a result of cheapness and greed. The bicycle industry standardized on 26 threads per inch, independent of fastener diameter, firstly to save money on thread-cutting machinery and secondly to make money selling these screw-ball fasteners to bike owners, because they weren't readily available from sources other than bicycle shops.

Of course there are also British Association (BA) threaded fasteners. I think it's interesting that so many BA threads are 25.4 TPI. Isn't that 10 threads per centimetre? If you look at the screw diameters in the BA series, I think you'll find that they're all round numbers of millimetres. It was a sneaky way of intrducing metric fasteners under a false banner.

Having worked in the fastener group at Boeing for a while, I concluded that the US fastener industry has developed a lot of very high tech stuff that the European industry still hasn't caught on to, but for the road vehicle environment, the old UK standards and the various kluges and add-ons seem to work OK - they're just a real PITA to try and identify when you're doing a rebuild.

My recommendation is that, if it's a nut and bolt, go for US standards. If it screws into a threaded hole, you're stuck with whatever the hole's thread is.

BTW, as defined in aerospace standards, a properly assembled bolted joint has no threads inside the holes in the components being joined. The threaded section of the bolt should end approximately 1/32" above the face of the joint and a 1/8" washer should be used between the nut and the joint face to allow the bolt to be properly tightened.
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