Annie 4-6-0: lost main rod to driver screw/pin, anyone know size?

[DennisT]

The screw attaching mainrod to side-rod/driver on an Annie 4-6-0 has been lost during a run on my friend's railroad.  He's expecting company end of this next week and is desparate for a fix.  I suspect this is a unique shouldered screw.  Does anyone know the thread size for this?  With screw/thread size, perhaps a temporary fastener can be improvised while Bachmann sends a replacement.  He may pull the screw out of the other side of the locomotive, but with fine threads like that it's hard to determine size by looking at it visually.
Any tip might put us in the right direction.

Thanks, Dennis

[Barry BBT]

Dennis,

I bought a tap for the rod post and it reads M3 X 0.5   Whatever that means.  Good luck.

Barry - BBT

[Loco Bill]

Sorry I didn't repl,y earlier.  I have had success using a large magnet along the right of way to pick up little screws and other small metal objects, you could try it!!