Morris Minor Owners Club

In the mid seventies my technical drawing teacher Mr Porter, always with a mind to the future of his students, gave his instruction in metric, imperial measurments faded along with primary school and has left me bereft of true and deep imperial understanding.
I'm in such a nut and bolt muddle as a direct consequence of my un- classic car education, so much so I'm thinking of measuring in mm all my nuts and bolts removed from the 1000 pickup and converting over to their equivelent in metric. Has anyone else done this, or am I in danger of straying from the true flavour of the morris minor. My bolts all need renewing, is this an opportunity to go over to metric?<br><br>

Dont sound a good idea to me, why not use the opertunity to further your understanding of imperial fixings?

No - you can't go metric! Why on earth would you ??

Get a decent set of taps and dies and clean a lot of the nuts and bolts up and re use. Any that are too far gone can easily be replaced from any minor specailist, as you have 2 stripped vehicles you probably have enough!!!

Some where on the site is a list of thread sizes and what they are used for.

Metric is a lot lot lot cheaper.... you get hundreds for the price of one imperial bolt! I'll admit I have put some metric bolts on mine..... purely for cost reasons... no one would tell..

Namrick UK sell a mixed bag of BSF (320 PIECES) Nuts bolts and washers 1/4 5/16 3/8 for £30,
mixed bag of UNF same size as above, 450 pieces at £15.75.
now excuse my thinkness, but does that mean the bolts head diameter, must do, I guess you get a mixture of bolt shaft lengths with this set. I take it minors have both UNF and BSF Thread

I guess it's because UNF is still used pretty universally in the USA like UNC. So are still mass produced.

Don't assume that because a bolt has a certain size head that it has a corresponding thread. For instance the wheel studs on the M1000 are 3/8UNF whereas the wheel nuts have 3/8 Whitworth heads.
The threads on the Series MM engine are metric or metric fine but the nut and bolt heads are all Whitworth. If you are unsure then check the bolts with a thread gauge.
Depending on the car a Minor can have any of the following threads:- BSF, BSW, UNF, UNC, Metric or Metric fine, requiring Whitworth or A/F spanners and maybe the occasional metric spanner.
There is also a BSP thread on the oil pressure light feed I believe.

davidmiles wrote:Namrick UK sell a mixed bag of BSF (320 PIECES) Nuts bolts and washers 1/4 5/16 3/8 for £30,
mixed bag of UNF same size as above, 450 pieces at £15.75.
now excuse my thinkness, but does that mean the bolts head diameter, must do, I guess you get a mixture of bolt shaft lengths with this set. I take it minors have both UNF and BSF Thread

Hi David

BSF and UNF sizes are measured in different ways - BSF & Whitworth are measured by the diameter of the shaft whereas UNF is the diameter of the head; As a very rough guide 1/2 UNF is approx the same size as 5/16 BSF and 13mm.

In the Namrick sets you do indeed get a variety of lengths in the 3 diameters.

Here is a link to the majority of sizes on the Minor
http://mmoc.org.uk/index.php?name=PNphp ... ic&t=18356

Rog

Just get a set of Metrinch sockets and spanners.... best present I ever got, love it and use it every time I work on the car.. One spanner for BSF, UNF and metric and they turn on the flats of the bolt so are less likely to slip......

I have to admit to having a set of Halfords ratchet spanners, the ones that have the positional rings, but these are only metric so sometimes work and sometimes don't... find they work wonders on things like manifold nuts that are tiresome without the ratchet function.

But as for the nuts and bolts themselves, I'd say use the same as the originals they lasted years so why change..???

i get all my nuts,bolts,washers and screws from bapp here int tarn metric and imperial bags full for £10/£15 depending on which bag i have

HarryMango wrote: BSF and UNF sizes are measured in different ways - BSF & Whitworth are measured by the diameter of the shaft whereas UNF is the diameter of the head; As a very rough guide 1/2 UNF is approx the same size as 5/16 BSF and 13mm.

Rog

Not strictly correct. All threads apart from BSP are described by the diameter of the plain shank, but spanners for UNF and UNC, and ISO metric are usually described by the A/F (across the flats) dimension of the hex nut or bolt head.

Thus a standard 5/16 inch UNF nut or bolt is 1/2 inch across its flats, and a standard 8mm bolt or nut is 13mm across its flats. Whitworth and BSF spanners are marked according to the size of standard nut or bolt they fit, so a 5/16 inch BSF nut needs a 5/16 BSF spanner (0.525 inches across the flats).

The complication with BSF and BSW is that that their heads are one spanner size smaller than "old" Whitworth, so a spanner marked "1/4 Whit" will fit 5/16BSF nuts and bolts. Some spanners are dual marked, e.g. 5/16 Whit / 3/8 BSF.

Some thread series are known by number scales, e.g. BA, but these again relate to diameters not spanner size.

As Mike also points out, some engines from the old Morris engine plant in Coventry also used a fine metric thread, but with nuts and hex heads to suit Whitworth spanners. Modern car manufacturers are also rather fond of non-ISO head sizes, such as 16mm A/F on 10mm bolts.

Kevin

Anyway - back to the original question of converting to metric...

In some cases it doesn't matter! The nuts and bolts that hold on the sill covers / sill finishers etc.. just use what you can get (unless you are entering concours).

For things like the front suspension lower arm bolts - it is advisable to stay with the original sizes, as these were intended to be a snug fit in the mating holes. Some of the nuts can't be changed to metric as you'd need different trunion pin and eyebolt pivot pin.
Wing bolts and door hinge bnolts - you have to stay original ue to the captive nuts...

So in short, where it really doesn't matter, use what you have. Where it does matter you need to use the right ones.
This leaves you needing Whitworth, Imperial and metric spanners.. My socket set has imperial and metric, and the only other socket I've ever needed was a 5/16" BSF (aka 1/4" Whitworth).
The steering wheel nut can be done with a Metric socket - and the same one fits the plug on the back of the master cylinder. The Minor 1000 wheel nuts are almost perfectly 18mm.

Modern car manufacturers are also rather fond of non-ISO head sizes, such as 16mm A/F on 10mm bolts.

or 15mm heads in some cases Like the engine mounting bolts squeezed between the mount and the inner wing, which, when rounded off because of the undersize head mean drastic measures in order to change a Fiat cambelt (It'll take me a while to forget that one!)