Drills and taps

There's nothing like the wrong size drill to make tapping a hole impossible, or a dull one to make a mess of a project.

Like any tool, a better tool works better.

 

Tap drill sizes

Size Dec.
Equiv.
A 0.2340
B 0.2380
C 0.2420
D 0.2460
E 0.2500
F 0.2570
G 0.2610
H 0.2660
I 0.2710
J 0.2770
K 0.2810
L 0.2900
M 0.2950
N 0.3020
O 0.3160
P 0.3230
Q 0.3320
R 0.3390
S 0.3480
T 0.3580
U 0.3680
V 0.3770
W 0.3860
X 0.3970
Y 0.4040
Z 0.4130