decimal equivalent, multiply mm times .03937. For exact mm equivalent, multiply decimal times 25.4.
Drill Bit Decimal Equivalency Chart
Fraction, Decimal Decimal
Number or Metric Equivalent Equivalent
Letter Size Size (in.) (mm)
Fraction, Decimal Decimal
Number or Metric Equivalent Equivalent
Letter Size Size (in.) (mm)
BITS
&
BLADES
58 0.0420 1.067
57 0.0430 1.092
1.10 0.0433 1.100
1.15 0.0453 1.150
56 0.0465 1.181
3/64 0.0469 1.191
1.20 0.0472 1.200
1.25 0.0492 1.250
1.30 0.0512 1.300
55 0.0520 1.321
1.35 0.0531 1.350
54 0.0550 1.397
1.40 0.0551 1.400
1.45 0.0571 1.450
1.50 0.0591 1.500
53 0.0595 1.511
1.55 0.0610 1.550
1/16 0.0625 1.588
1.60 0.0630 1.600
52 0.0635 1.613
1.65 0.0650 1.650
1.70 0.0669 1.700
51 0.0670 1.702
1.75 0.0689 1.750
50 0.0700 1.778
1.80 0.0709 1.800
1.85 0.0728 1.850
49 0.0730 1.854
1.90 0.0748 1.900
48 0.0760 1.930
1.95 0.0768 1.950
5/64 0.0781 1.984
47 0.0785 1.994
2.00 0.0787 2.000
2.05 0.0807 2.050
46 0.0810 2.057
45 0.0820 2.083
2.10 0.0827 2.100
2.15 0.0846 2.150
44 0.0860 2.184
2.20 0.0866 2.200
2.25 0.0866 2.250
80 0.0135 0.343
0.35 0.0138 0.350
79 0.0145 0.368
0.38 0.0150 0.380
1/64 0.0156 0.396
0.40 0.0157 0.400
78 0.0160 0.406
0.42 0.0165 0.420
0.45 0.0177 0.450
77 0.0180 0.457
0.48 0.0189 0.480
0.50 0.0197 0.500
76 0.0200 0.508
75 0.0210 0.533
0.55 0.0217 0.550
74 0.0225 0.572
0.60 0.0236 0.600
73 0.0240 0.610
72 0.0250 0.635
0.65 0.0256 0.650
71 0.0260 0.660
0.70 0.0276 0.700
70 0.0280 0.711
69 0.0292 0.742
0.75 0.0295 0.750
68 0.0310 0.787
1/32 0.0312 0.792
0.80 0.0315 0.800
67 0.0320 0.813
66 0.0330 0.838
0.85 0.0335 0.850
65 0.0350 0.889
0.90 0.0354 0.899
64 0.0360 0.914
63 0.0370 0.940
0.95 0.0374 0.950
62 0.0380 0.965
61 0.0390 0.991
1.00 0.0394 1.000
60 0.0400 1.016
59 0.0410 1.041
1.05 0.0413 1.050
Copyright 2004 Robert Bosch Tool Corporation. All rights reserved.
3.90 0.1535 3.900
23 0.1540 3.912
5/32 0.1562 3.967
22 0.1570 3.988
4.00 0.1575 4.000
21 0.1590 4.039
20 0.1610 4.089
4.10 0.1614 4.100
4.20 0.1654 4.200
19 0.1660 4.216
4.30 0.1693 4.300
18 0.1695 4.305
11/64 0.1719 4.366
17 0.1730 4.394
4.40 0.1732 4.400
16 0.1770 4.496
4.50 0.1772 4.500
15 0.1800 4.572
4.60 0.1811 4.600
14 0.1820 4.623
13 4.70 0.1850 4.700
3/16 0.1875 4.762
12 4.80 0.1890 4.800
11 0.1910 4.851
4.90 0.1929 4.900
10 0.1935 4.915
9 0.1960 4.978
5.00 0.1969 5.000
8 0.1990 5.054
5.10 0.2008 5.100
7 0.2010 5.105
13/64 0.2031 5.159
6 0.2040 5.182
5.20 0.2047 5.200
5 0.2055 5.220
5.30 0.2087 5.300
4 0.2090 5.309
5.40 0.2126 5.400
3 0.2130 5.410
5.50 0.2165 5.500
7/32 0.2188 5.558
5.60 0.2205 5.600
Fraction, Decimal Decimal
Number or Metric Equivalent Equivalent
Letter Size Size (in.) (mm)
Fraction, Decimal Decimal
Number or Metric Equivalent Equivalent
Letter Size Size (in.) (mm)
43 0.0890 2.261
2.30 0.0906 2.300
2.35 0.0925 2.350
42 0.0935 2.375
3/32 0.0938 2.383
2.40 0.0945 2.400
41 0.0960 2.438
2.45 0.0965 2.450
40 0.0980 2.489
2.50 0.0984 2.500
39 0.0995 2.527
38 0.1015 2.578
2.60 0.1024 2.600
37 0.1040 2.642
2.70 0.1063 2.700
36 0.1065 2.705
7/64 0.1094 2.779
35 0.1100 2.794
2.80 0.1102 2.800
34 0.1110 2.819
33 0.1130 2.870
2.90 0.1142 2.900
32 0.1160 2.946
3.00 0.1181 3.000
31 0.1200 3.048
3.10 0.1220 3.100
1/8 0.1250 3.175
3.20 0.1260 3.200
30 0.1285 3.264
3.30 0.1299 3.300
3.40 0.1339 3.400
29 0.1360 3.454
3.50 0.1378 3.500
28 0.1405 3.569
9/64 0.1406 3.571
3.60 0.1417 3.600
27 0.1440 3.658
3.70 0.1457 3.700
26 0.1470 3.734
25 0.1495 3.797
3.80 0.1496 3.800
24 0.1520 3.861
®
For exact decimal equivalent, multiply mm times .03937. For exact mm equivalent, multiply decimal times 25.4.
Drill Bit Decimal Equivalency Chart (cont'd.)
BITS
&
BLADES
Copyright 2004 Robert Bosch Tool Corporation. All rights reserved.
Fraction, Decimal Decimal
Number or Metric Equivalent Equivalent
Letter Size Size (in.) (mm)
Fraction, Decimal Decimal
Number or Metric Equivalent Equivalent
Letter Size Size (in.) (mm)
2 0.2210 5.613
5.70 0.2244 5.700
1 0.2280 5.791
5.80 0.2283 5.800
5.90 0.2323 5.900
A 0.2340 5.944
15/64 0.2344 5.954
6.00 0.2362 6.000
B 0.2380 6.045
6.10 0.2402 6.100
C 0.2420 6.147
6.20 0.2441 6.200
D 0.2460 6.248
6.30 0.2480 6.300
E 0.2500 6.350
6.40 0.2520 6.400
6.50 0.2559 6.500
F 0.2570 6.528
6.60 0.2598 6.600
G 0.2610 6.629
6.70 0.2638 6.700
17/64 0.2656 6.746
H 0.2660 6.756
6.80 0.2677 6.800
6.90 0.2717 6.900
I 0.2720 6.909
7.00 0.2756 7.000
J 0.2770 7.036
7.10 0.2795 7.100
K 0.2810 7.137
9/32 0.2812 7.142
7.20 0.2835 7.200
7.30 0.2874 7.300
L 0.2900 7.366
7.40 0.2913 7.400
M 0.2950 7.493
7.50 0.2953 7.500
19/64 0.2969 7.541
7.60 0.2992 7.600
N 0.3020 7.671
7.70 0.3031 7.700
7.80 0.3071 7.800
7.90 0.3110 7.900
5/16 0.3125 7.938
8.00 0.3150 8.000
O 0.3160 8.026
8.10 0.3189 8.100
8.20 0.3228 8.200
P 0.3230 8.204
8.30 0.3268 8.300
21/64 0.3281 8.334
8.40 0.3307 8.400
Q 0.3320 8.433
8.50 0.3346 8.500
8.60 0.3386 8.600
R 0.3390 8.611
8.70 0.3425 8.700
11/32 0.3438 8.733
8.80 0.3465 8.800
S 0.3480 8.839
8.90 0.3504 8.900
9.00 0.3543 9.000
T 0.3580 9.093
9.10 0.3583 9.100
23/64 0.3594 9.129
9.20 0.3622 9.200
9.30 0.3661 9.300
U 0.3680 9.347
9.40 0.3701 9.400
9.50 0.3740 9.500
3/8 0.3750 9.525
V 0.3770 9.576
9.60 0.3780 9.600
9.70 0.3819 9.700
9.80 0.3858 9.800
W 0.3860 9.804
9.90 0.3898 9.900
25/64 0.3906 9.921
10.00 0.3937 10.000
X 0.3970 10.084
10.20 0.4016 10.200
Y 0.4040 10.262
13/32 0.4062 10.317
Z 0.4130 10.490
®
For exact decimal equivalent, multiply mm times .03937. For exact mm equivalent, multiply decimal times 25.4.
Drill Bit Decimal Equivalency Chart (cont'd)
BITS
&
BLADES
Copyright 2004 Robert Bosch Tool Corporation. All rights reserved.
Fraction, Decimal Decimal
Number or Metric Equivalent Equivalent
Letter Size Size (in.) (mm)
Fraction, Decimal Decimal
Number or Metric Equivalent Equivalent
Letter Size Size (in.) (mm)
10.50 0.4134 10.500
27/64 0.4219 10.716
10.80 0.4252 10.800
11.00 0.4331 11.000
7/16 0.4375 11.112
11.20 0.4409 11.200
11.50 0.4528 11.500
29/64 0.4531 11.509
11.80 0.4646 11.800
15/32 0.4688 11.908
12.00 0.4724 12.000
12.20 0.4803 12.200
31/64 0.4844 12.304
12.50 0.4921 12.500
1/2 0.5000 12.700
12.80 0.5039 12.800
13.00 0.5118 13.000
33/64 0.5156 13.096
13.20 0.5197 13.200
17/32 0.5312 13.492
13.50 0.5315 13.500
13.80 0.5433 13.800
35/64 0.5469 13.891
14.00 0.5512 14.000
14.25 0.5610 14.250
9/16 0.5625 14.288
14.50 0.5709 14.500
37/64 0.5781 14.684
14.75 0.5807 14.750
15.00 0.5906 15.000
19/32 0.5938 15.083
15.25 0.6004 15.250
39/64 0.6094 15.479
15.50 0.6102 15.500
15.75 0.6201 15.750
5/8 0.6250 15.875
16.00 0.6299 16.000
16.25 0.6398 16.250
41/64 0.6406 16.271
16.50 0.6496 16.500
21/32 0.6562 16.669
16.75 0.6594 16.750
17.00 0.6693 17.000
43/64 0.6719 17.066
17.25 0.6791 17.250
11/16 0.6875 17.462
17.50 0.6890 17.500
45/64 0.7031 17.859
18.00 0.7087 18.000
23/32 0.7188 18.258
18.50 0.7283 18.500
47/64 0.7344 18.654
19.00 0.7480 19.000
3/4 0.7500 19.050
49/64 0.7656 19.446
19.50 0.7677 19.500
25/32 0.7812 19.845
20.00 0.7879 20.000
51/64 0.7969 20.241
20.50 0.8071 20.500
13/16 0.8125 20.638
21.00 0.8268 21.000
53/64 0.8281 21.034
27/32 0.8438 21.433
21.50 0.8465 21.500
55/64 0.8594 21.829
22.00 0.8661 22.000
7/8 0.8750 22.225
22.50 0.8858 22.500
57/64 0.8906 22.621
23.00 0.9055 23.000
29/32 0.9062 23.017
59/64 0.9219 23.416
23.50 0.9252 23.500
15/16 0.9375 23.812
24.00 0.9449 24.000
61/64 0.9531 24.209
24.50 0.9646 24.500
31/32 0.9688 24.608
25.00 0.9843 25.000
63/64 0.9844 25.004
1 1.0000 25.400