TABLE II-VIII. DECIMAL MILLIMETER EQUIVALENTS OF DRILL SIZES
Decimal/Millimeter Equivalents of Drill Sizes From 1/2" to No. 80
Size
Decimal Millimeter
Size
Decimal Millimeter
Size
Decimal
Millimeter
Size
Decimal Millimeter
Equiv.
Equiv.
Equiv.
Equiv.
Equiv.
Equiv.
Equiv.
Equiv.
1/2
0.500
12.7000
G
0.261
6.6294
5/32
0.1562
3.9687
51 0.067
1.7018
31/64
0.4843
12.3031
F
0.257
6.5278
23
0.154
3.9116
52 0.0635
1.6129
15/32
0.4687
11.9062
E-1/4
0.250
6.3500
24
0.152
3.8608
1/16 0.0625
1.5875
29/64
0.4531
11.5094
D
0.246
6.2484
25
0.1495
3.7973
53 0.0595
1.5113
7/16
0.4375
11.1125
C
0.242
6.1468
26
0.147
3.7338
54 0.055
1.397
27/64
0.4218
10.7156
B
0.238
6.0452
27
0.144
3.6576
55 0.052
1.3208
Z
0.413
10.4902
15/64
0.2343
5.9531
9/64
0.1406
3.5719
3/64 0.0468
1.1906
13/32
0.4062
10.3187
A
0.234
5.9436
28
0.1405
3.5687
56 0.0465
1.1811
Y
0.404
10.2616
1
0.228
5.7912
29
0.136
3.4544
57 0.043
1.0922
X
0.397
10.0838
2
0.221
5.6134
30
0.01285
3.2639
58 0.042
1.0668
25/64
0.3906
9.9212
7/32
0.2187
5.5562
1/8
0.125
3.1750
59 0.041
1.0414
W 0.386
9.8044
3
0.213
5.4102
31
0.120
3.048
60 0.040
1.016
V
0.377
9.5758
4
0.209
5.3086
32
0.116
2.9464
61 0.039
0.9906
3/8
0.375
9.5250
5
0.2055
5.2197
33
0.113
2.8702
62 0.038
0.9652
U
0.368
9.3472
6
0.204
5.1816
34
0.111
2.8194
63 0.037
0.9398
23/64
0.3593
9.1262
13/64
0.2031
5.1594
35
0.110
2.794
64 0.036
0.9144
T
0.358
9.1281
7
0.201
5.1054
7/64
0.1093
2.7781
65 0.035
0.899
S
0.346
8.7884
8
0.199
5.0546
36
0.1065
2.7051
66 0.033
0.8382
11/32
0.3437
8.7300
9
0.196
4.9784
37
0.104
2.6416
1/32 0.0312
0.7937
R
0.339
8.6106
10
0.1935
4.9149
38
0.1015
2.5781
67 0.032
0.8128
Q
0.332
8.4328
11
0.191
4.8514
39
0.0995
2.5273
68 0.031
0.7874
21/64
0.3281
8.3337
12
0.189
4.8006
40
0.098
2.4892
69 0.029
0.7366
P
0.323
8.2042
3/16
0.1875
4.7625
41
0.096
2.4384
70 0.028
0.7112
O
0.316
8.0264
13
0.185
4.699
3/32
0.0937
2.3812
71 0.026
0.6604
5/16
0.3125
7.9375
14
0.182
4.6228
42
0.0935
2.3749
72 0.025
0.635
N
0.302
7.6708
15
0.180
4.572
43
0.089
2.2606
73 0.024
0.0696
19/64
0.2968
7.5387
16
0.177
4.4958
44
0.086
2.1844
74 0.0229
0.58166
M
0.295
7.4930
17
0.173
4.3942
45
0.082
2.0828
75 0.021
0.5334
L
0.290
7.3660
11/64
0.1718
4.3656
46
0.081
2.0574
76 0.020
0.508
9/32
0.2812
7.1425
18
0.1695
4.3053
47
0.0785
1.9939
77 0.018
0.4572
K
0.281
7.1374
19
0.166
4.2164
5/64
0.0781
1.9844
1/64 0.0156
0.3969
J
0.277
7.0358
20
0.161
4.0894
48
0.076
1.9304
78 0.016
0.4064
I
0.272
6.9088
21
0.159
4.0386
49
0.073
1.8542
79 0.0145
0.3683
H
0.266
6.7564
22
0.157
3.9878
50
0.070
1.778
80 0.0135
0.3429
17/64
0.2656
6.7462
DRILL SIZES AVAILABLE
Drill may be obtained in regular sizes to a 4 inch diameter, and increase
in 64ths of an inch. The regular metric drills vary from 2 to 76mm and
increase in 0.5mm variations.
PIPER AIRCRAFT
PA-28-161 CADET
AIRPLANE MAINTENANCE MANUAL
Issued: FEBRUARY 28, 1989
HANDLING AND SERV I C I N G
1D9