cylinder head

I think this is the one you want:-

https://www.rgmnorton.co.uk/buy/cylinder-head-box-spanner-1-4-whit-both-ends_540.htm

or

https://andover-norton.co.uk/en/shop-details/17198/box-spanner-1-4-x-3-16-whit-cylinder-head-

Tony

investing in a set of 3/8" drive sockets to complement your Norton? In my experience it is always best to use the right sizes, otherwise pain and damage can occur. 

Something like "Sealey AK2676 7pc 3/8"Sq Drive Whitworth Socket Set" isn't too expensive to have in your toolbox.

Same thing with regard to a set of imperial A/F sockets, e.g. Sealey AK2672 Socket Set 11Pc 3/8" Sq Drive 12Pt Walldrive Imperial.

Both are available on Amazon.

Other makes of socket and other suppliers are available. 

That way you won't have to be guessing as to which one to use?

Regards,

George

A 3/8" drive, 1/4 whitworth socket, but I have a Dominator not a Commando. Certainly clears the fins ok on my engine.

I'm sure my Whitworth sockets are by Britool.

Hope this helps.

Regards, George.

Hello all well I use a set of box spanners that I made up just for Cylinder head removal and fitting witch have been adapted so I can fit my Toque wrench on to them and have some cranked spanners made for the under nuts to buy good box spanners go to EBay vintage tools and engineering tools .yours Anna j

Phillippe...it seems like those nuts on the Commando are the old Whitworth sizes as used extensively on the Dommie, which is why your sockets (which are sized 'across flats') won't fit. So you need the box spanner suggested by Tony. It looks like the Sealy set has 'AF' sizes, so they won't fit.

Hi Philippe,

Unlike metric and AF spanners, the Whitworth series are sized according to the thread size, not the distance across the flats.

At some point in history (Wartime to save weight and material maybe?) The hexagon sizes were reduced such that a spanner that fitted a 3/16" nut now fitted a 1/4", and the 1/4" Whit spanner now would fit a 5/16" nut.

I believe a 1/4 Whit nut has an AF size of around 13.3mm, i.e just bigger than 13mm but not as big as 9/16"AF

It is worth looking up the history of Joe Whitworth - he created the first ever standardised series of fasteners, similar to the metric system we enjoy today.

Hope that this helps.

Regards, George 

Hi All,

         I use a 17/32" AF socket, 3/8" drive. (Britool). Happen to have the tank off at the moment, so I just checked to make absolutely certain.

Regards

Gary

I have a 1/4 drive metric socket set that I always use that on those three cylinder head bolts (or nuts). It must be either the 13 mm or 14 mm that fits it OK, the benefit is that you can get a torque wrench on to the socket.

The Club's spares store sells a very adequate range of Whitworth spanners (double open-end and combination) and 3/8" drive sockets, at highly competitive prices.

I can also recommend the Andover Norton toolkit, which offers very high quality tools at a reasonable price. Since I gather that you are relatively new to Commandos you should consult the list of special tools in the Workshop Manual.

Depending on the state of the hexagons on your bike's current nuts and bolts you may want to consider Metrinch spanners and sockets. As the name suggests they are cunningly designed to accommodate multiple systems, by bearing on the flanks of the hexagon, not the points—and are hence very useful in dealing with rounded-off fasteners.

If this sounds a lot, remember that one can never have too many tools, especially if working on a Commando.

Ah … just looked, and it says "out of stock". Looks like you'll have to contact the NOC shop volunteers: see https://www.nortonownersclub.org/nocshop# for contact details.

Bear in mind that they're volunteers when holding your breath for a reply (but I've always found them extremely responsive).

I got thin wall King Dick sockets from RGM.

My solution (Mk3 too) was to scrounge from work a suitably sized 1/2" drive bi-hex socket and 6" extension - the type with an integral tommy bar through hole as well as the normal square drive - and got RAF station workshops to braze the two together and then grind the socket down until it was an easy fit in the head; it worked perfectly.  Kept it in the toolbox for years after the Mk3 went and now with another Mk3 in residence, it is unexpectedly back in use.  I did try it on my Atlas a few years ago and it did not fit those nuts.

Andy

What a small world. I worked for a company that used to make these spanners in the sixties for Churchill Tools. We made lots for the car industry as well. Still got one or two in the tool box. I bought a new 200 piece Halfords Professional Socket Set on ebay last year for £130 delivered. Worth keeping a look out as there is everything you need in the set. I bought some huge Britool ring spanners on local boot sale for £1 each a few years ago, you can hit them with a sledge if bolts are tight! I bought all my whitworth spanners and sockets in the sixties as a first year apprentice, all elora or britool, never wear out.