SIZE	THREADS per INCH	TAP DRILL SIZE (mm)
1/8"	40	2.55
5/32"	40	3.20
3/16"	40	3.95
7/32"	40	4.75
1/4"	40	5.50
9/32"	32	6.10
5/16"	32	7.00
3/8"	32	8.60