X Drill Size

A X letter drill is 0.3970" (10.084 mm).

Closest fraction: 25/64 (0.3906", under by 0.0064").

Next size down / up

Drill	Inch	mm
10 mm	0.3937	10.000
Y	0.4040	10.262

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