Welcome to our resource for MG Car Information.



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 - BA thread size

Thanks to all that responded to my request of thread size on TF wiper knobs. I actually obtained some 7BA screws that fitted shaft, as the shaft is only 1/4" 2ba would weaken it too much. I did find some interesting information on BA sizes, even BA numbers refer to engineering and the odd numbers refer to electrical,just shows what information is out there.
Regards, Adrian Wells.
Thomas WELLS

Hi Adrian,

I wonder why such a small thread is used on your car -there is a considerable twisting force on the screw when turning on and parking blades. Bearing in mind the diam. of the shaft 4BA seems about right, and looks original. I've a full set of BA taps and dies, 0-10, but the odd sizes were rarely used, although 5BA was used by Lucas for motorcycle switches!


J C Mitchell

5BA is also used to secure the upper points spring to the pedestal in SU fuel pumps, whereas 2BA are used to secure the pedestal to the coil housing and the coil housing to the pump body. This would seem to be in keeping with what Thomas found regarding even and odd numbers for BA fasteners. Cheers - Dave
David DuBois

This thread was discussed between 07/09/2011 and 08/09/2011

MG TD TF 1500 index

This thread is from the archive. The Live MG TD TF 1500 BBS is active now.