Little screw wot holds the ignition switch in the barrel. Size?

[chrishawley]

Here's a hard one. One some vehicles the ignition switch is held in the lock barrel (Waso or Britax type)  by a tiny screw. In effect a grub screw 'cept Phillips headed - just enough to nip the switch in place.

Mine's gone missing. Any clues on what thread/size it might be? Offering up what I had to hand it's <3mm and <no6 unf.

Suggestions?

[dougbgt6]

Oh, Chris, tricky! I've had it apart and it's a bugger to get back in! However, if it's not there, it's fallen out and it's on the floor, somewhere! Sorry no help at all! 

Doug

[PeteH]

Age of the device, would suggest, not metric?. Which leaves the likes of A-F. U-N. BSW/F. and even, but less likely B-A. Have you tried to size the hole?. The drill size, would give a clue to the thread. Eg; 3.5mm, would suggest a UNF 8-36tpi.

Pete

[chrishawley]

Thanks.

Nearest approximation to the internal diameter of the thread ≈ 2.5 mm. Would kind of put is close to no.4 unf/c or (arrrghh) 7BA!!!

 

Guess I'm being lazy, really. I suppose the practical thing is to remove the mechanism from the car a resize the hole to M3 coarse.

[PeteH]

7 minutes ago, chrishawley said:

I suppose the practical thing is to remove the mechanism from the car a resize the hole to M3 coarse.

One aproach, In my case I would be trying everything I have in the (Huge) "odds and sods" bin aquired over 60 years with additions from Father and Father in Laws Garages. Not that long back I came across a 1" "Acme" threaded bolt of inderterminate age!, from "who" knows where!.😁 And some screws I Know came from my BSA B30 when I replaced them with "Allen" Socket screws, courtesy of my then employer. (Tut- Tut)

Pete.

[Pete Lewis]

think i have a 1" acme threaded screw form a rail chair to sleeper bolt 

has a washer faced head ..  now  where is it hiding 

Pete