Metric and Imperial Screw Sizes

[DRIFT_BUGGY]

I just realised that the screws that hold the shock pinion on the shaft is 2-56 x 1/4" and the screw looked about that size so I thought I would try it on the motor and it fit but you could wobble the screw a tiny bit in the hole. But isn't 2-56 bigger than 0-80?