13/64 and 1/4-20 iirc. EDIT 13/64 for the drill bit and 1/4-20 for the tap and plug. To plug it a 1/4 coarse thread stud with the female recess for an allen wrench to screw it in works good. Just pick the right length

Last edited by RapidRobert; 11/18/14 10:18 PM.
live every 24 hour block of time like it's your last day on earth