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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - BSC Thread

I've been advised that yet another British thread was used on the TD and TF, that being British Standard Cycle. Apparently the chrome wing nut, the chrome acorn nut and the brass nut threads on the windscreen are 5/16" BSC on both the TD and TF and presumably on other T Types. Can anyone confirm this? Cheers
Peter TD 5801
P Hehir

Try searching archive "windscreen stud thread". Several old threads pop up with info from several that are no longer with us. George
George Butz III

Peter,
there is some debate on the threads in the w/screen frame. British standard threads
British Cycle Thread 5/16 x 26tpi-- 60deg
British Brass Thread 5/16 X 26tpi-- 55deg
I would say Brass as this was Industry Standard in the 50's.
British Cycle was used only in pedal cycles and motorcycles as far as I can remember.
The studs in the windscreen also have a locking pin driven in before chroming don't attempt to remove them. Don't ask me how I know !!!!!
Ray TF 2884
Ray Lee

Thanks Ray and George. The British Brass thread is a new one on me. I have a chart somewhere in my workshop that lists all thread types and I don't recall ever seeing British Brass. It's a good day when I learn something new. I was aware of BSF, BSC, (which I had once erroneously assumed stood for British Standard Coarse) BSPP, BSPT (parallel and taper) and BA. I'll check out the archive and the chart also, if and when I find it. Cheers
Peter TD 5801
P Hehir

Peter,
The speedo drive on the gearbox also has a BSB thread-so has the filler plug on the Armstrong dampers.
Regards
Declan
Declan Burns

You won't find British Standard Brass on a list of British Standards because the terminology is erroneous - it never was an official BS and should just be called British Brass Thread.
Dave H
Dave Hill

Explanation of Brass Threads and Cycle Threads on British Tools & Fasteners site:

British Standard Brass
https://britishfasteners.com/threads/bsb.html

British Standard Cycle
https://britishfasteners.com/threads/bsc.html

Lonnie
TF7211
LM Cook

That's a good site Lonnie. Plenty of info there. It seems BSB was used on brass tube fittings which suggests that the windscreen items mentioned below were much more likely to be BSC. They use the British Standard Brass terminology Dave. Cheers
Peter TD 5801
P Hehir

As do many others, but not a British Standard in reality. The logic for the windscreen fittings being British Standard Cycle Thread seems correct to me.
Dave H
Dave Hill

Peter
You'd probably need a magnifying glass but could probably use thread gauges and see if you can pick up the difference between 55 and 60 thread angles on an unworn part of the thread

willy

Or take a closeup with macro and blow it up and measure the angle - ?
William Revit

Willy the initial request came from someone who wanted a tap and die to clean up the threads. It seems that as they are so close either may do the job. He had no luck sourcing BSC gear here so perhaps the brass thread may be easier to get hold of. I'll pass the info on. Cheers
Peter TD 5801
P Hehir

Peter,

Check eBay. Shipping to you from China or India may be cheap. I assume that the die will be used to chase the threads instead of cutting raw brass. So it probably doesn't need to be NASA quality. Over twenty British Cycle thread items on U.S. eBay. Australian eBay may have different sellers and prices.

Interesting, I saw a set from India labeled as "BSCY/BSB TAP DIE SET - 26 TPI - 60 DEGREE ANGLE". British Brass has 55-deg thread angle. British Cycle has 60-deg. So double-check the specs.

Don't laugh, I bought a couple of cheap British Standard Parallel Pipe taps from China for my radiator. One was $10.99 delivered and was really nice. The other was $6.99 delivered and was usable. Both arrived fast.

Lonnie
TF7211
LM Cook

Tracy Tools in the UK have them.
Dave H
Dave Hill

This thread was discussed between 01/07/2019 and 03/07/2019

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