Lettered Twist Drill Sizes
Letter
Diameter
(inches)
A
.234
B
.238
C
.242
D
.246
E
.250
F
.257
G
.261
H
.266
I
.272
J
.277
K
.281
L
.290
M
.295
N
.302
O
.316
P
.323
Q
.332
R
.339
S
.348
T
.358
U
.368
V
.377
W
.386
X
.397
Y
.404
Z
.413