Size and Thread Pitch of AEG Stock Bolt
 

I knew this once, but my old memory has lost it.

Does anyone know the size and thread pitch of the bolt that hold the stock to the gearbox (spring guide) of an M4 AEG?

I think it is M5, 0.8mm pitch.

Thanks.

I think the SAE equivalent is 8 x 32?

There a no SAE equivalent. You will jam/strip everything if you do that.

Technically, it would be a bit larger than #10, and 31.75tpi.
A #10-32 could be forced in there, but results would be less than professional looking.

actually truth be told, a 10-32 fits perfectly in an M5x0.8 threaded hole, almost like it was meant to thread in there. The smaller diameter takes up the slack of the screw pitch being ever so slightly off.
Done it myself, and the tolerances are close enough you could get away with in for sure on an AEG

I think I once fitted (or forced) a M5, 0.8mm pitch bolt into a SAE nut... Or maybe it was the other way.
A little tight, but the result was OK for an AEG.