top of page

Pre Tap Drill Size

Inch Form Tap

Tap
Drill Size
Decimal Equivalent
5/16-24
M
0.2950
5/16-18
L
0.2900
1/4-28
15/64
0.2340
1/4-20
1
0.2280
12-28
7
0.2010
12-24
8
0.1990
10-32
16
0.1770
10-24
11/64
0.1719
8-36
24
0.1520
8-32
25
0.1495
6-40
3.25mm
0.1280
6-32
1/8
0.1250
bottom of page