Smiths chronometric speedo

[tractorman]

I have a Smith chronometric speedo with a rather poor condition dial and by a stroke of luck I happen to have a brand new replacement dial, however only one of the 4 fixing screws is present, and I am struggling to identify what the screws are, they measure 0.077" OD and are 56 tpi of near abouts which doesn’t relate to any thread standard I know, and ideas what they are and more importantly, where can I get some ?

[Goldy]

Speedograph repair Smiths but I dont know if they sell spares. Worth a try though. http://www.speedograph-richfield.com/

[stu.andrews]

Check out Mr Pople at Frimley, Hants tel no.  01252-329826.  He's very helpful & has done some good repairs for me.

[L.A.B.]

I am struggling to identify what the screws are, they measure 0.077" OD and are 56 tpi of near abouts which doesn’t relate to any thread standard I know,

That's because the screws are METRIC size!

It was the French Jaeger company that originally developed the Chronometric design, as a result of that Smiths (who bought Jaeger) Chronometrics have metric dimensions and metric screw threads.
http://velobanjogent.blogspot.com/2008/03/smiths-chronometric-speedometer-and_21.html