Series 2/2a dashboard bolts - thread ?

[JohnboyLandy]

Hi All, just wondering what thread the three bolts are at the top of the dashboard panel that thread into the captive nuts ?

It looks like 3/16, but I don't think they are unf, but maybe bsf ?

Thanks
John

[mick88]

Cheers, Mick.

[B.S.F.]

Hi All, just wondering what thread the three bolts are at the top of the dashboard panel that thread into the captive nuts ?It looks like 3/16, but I don't think they are unf, but maybe bsf ?ThanksJohn

2B.A. x 3/4"

It's the same thread as used on the speedo cable retaining plate at the gearbox end, and for the choke warning light switch on the head.
.W.

[JohnboyLandy]

Thanks BSF, is 2B.A a pipe thread ????

Cheers,
JOhn

[incisor]

British Tools & Fasteners - BA Thread Profile

will fill you in

[gromit]

Thanks BSF, is 2B.A a pipe thread ????

British Association thread, often used for old electrical equipment in the UK, also instrumentation & model engineering (although there is also a model engineers thread form).

Difficult/expensive to find nowadays.
https://www.classicfasteners.com.au/ba/



Colin

[JohnboyLandy]

Thanks Colin (and others) that explains it now I can see the pictures.

Cheers,
John

[mick88]

Thanks BSF, is 2B.A a pipe thread ????

Cheers,
JOhn

No, BSPP (Parallel) and BSPT (Taper) are British pipe threads.

Cheers, Mick.

[OneOff]

If you were so inclined It converts to 5mm quite well... just sayin’

not that I would do a thing like that

[JDNSW]

I was debating whether to mention that.......

Surprisingly for a 19th century British thread form, BA is a metric thread - but the thread form is much sharper (smaller angle) than ISO metric.