Does anyone know what thread is on the original pivot fulcrum of the clutch and brake lever on the WD Matchless G3L?

I have measured the TPI which came out at 28 which is 1/4 UNF but the thread on the fulcrum is smaller than 1/4 inch.

Ideally I need the two nuts but these have been difficult to get hold of

If I can identify what thread I can buy the relevant tap to make some?

Hope this makes sense to somebody .....

I think they were BA.

email (option): davmax@ntlworld.com

0BA. You can buy them ready made in stainless from Dave Middleton.

http://www.stainlessmiddleton.co.uk/product-selected.php?id=2190&category=Nuts%20(Full)&subcategory=B.A.

Ron

email (option): ronpier@talk21.com

try les at russell motors, he should have em. i dont think he works fridays now.
im sure its 1/4 whitworth nuts i use,

barry

Thank you for the replies, I tried Les with no joy.

Thank you for the BA lead ... The exact TPI was 28.2 which is 1BA. Needless to say I have now ordered some!

Hi,I don't know how you measured the pitch to the accuracy stated, but here is the
run down on BA threads.Being involved daily in reproducing threads of various types and
pitches,thread forms and etc etc, this is the one that always stumps most of us.The stated diameter of course,is always a factor to slip you up as there is always the
running clearance to take into consideration.On these smaller threads,a couple of "thous" can make a big difference in identifying the correct thread.
Having said that here is the article.The gear trains to screw cut these pitches are beyond my mathematical skills.


http://en.wikipedia.org/wiki/British_Association_screw_threads

cheers Rick

email (option): richardholt@rocketmail.com

My mistake on the size of the pivot screws then. I remember that the two studs on the back of the speedo are 0BA. Which is why they are wobbly when you use 1/4" BSC/BSF nuts Ron

email (option): ronpier@talk21.com

My mistake on the size of the pivot screws then. I remember that the two studs on the back of the speedo are 0BA. Which is why they are wobbly when you use 1/4" BSC/BSF nuts Ron[/quote]

Running Clearence !!!!!

And here in lies the problem.1/4" BSC / BSF / brass all have the same number of TPI but different thread depth & angles so while they will thread onto each other they do not actually fit.

A 1/4 bsw galvanised bolt usually will not thread into a 1/4" BSW zinc plated nut but the reverse will fit together.

email (option): wariron@tpg,com,au