Screw size for retaining the chrome knobs on the dash

Can anybody tell me the size of the grub screws that hold the chrome knobs on the dash in place, I have tried a few 2BA and 3BA but no luck

I thought it was 2BA.

No Rob tried them, getting a bit frustrated with this one will have to buy a BA tap and make them slightly larger maybe, I have had a couple of them re chromed and they my be tight fits now but have tried to get something to fit to no avail yet
anybody used anything a a substitute

waiting to put my dash back in but cannot find anything that will fit
Polti is in the same boat !

Mine are 2BA

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Hi Rob, is that on your 120 or MKIV I have tried 2BA on the chromed knobs for the windscreen wipers and heater controls on my MKIV but no fit, interesting shape, I had taken mine out and lost them somewhere along with the green heater on lens, frustrating, I need to get something made up. maybe Coventry auto spares the 120 specialist may be able to help ?

Hi Mike,
I taped 4 mm tread and used grub screws 4 x 4 mm with hexagone screw head

I thank you sir,
I will, try that


The picture I posted is a screw from a knob on my '38 SS.
It was definitely 2BA with the end machined down to fit in the shaft of the control.

If you are in America, #10-32 UNF is almost the same as 2BA, which is about 31.4 tpi, so you could get some set screws and a tap and rework your knobs to take them.

Thanks both
I don’t know why the 2BA did not fit however I have tapped a 4mm hole and fitted 4 mm set screws so all is fine now, all the help much appreciated
I am sure there will be anther topic coming along from me in the very near future !