R Drill Size

A R letter drill is 0.3390" (8.611 mm).

Closest fraction: 11/32 (0.3438", over by 0.0047").

Next size down / up

Drill	Inch	mm
8.5 mm	0.3346	8.500
11/32	0.3438	8.731

Printable PDF version - Drill Size Chart
Clean letter-size sheet for the toolbox or shop wall. Instant download, $3.49.