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Standard drill bit sizes for CNC machining

Use these conversion tables of standard drill bit sizes (metric, fractional inch, and wire gauge) common in CNC machining to reduce manufacturing costs from custom tooling.

Standard Drill Bit Sizes for CNC machining (Conversion Tables)

Custom tooling can quickly increase your manufacturing costs. Knowing how to get the most out of standard tooling can save you a significant amount of money on producing custom parts.

To reduce the need for custom tooling, we have created these three tables to summarize the standard drill bit sizes used in CNC machining.

Drill bit size charts

The three tables below provide standard, fractional inch and wire gauge drill bit sizes. It's helpful, and often essential, to match these standard sizes when designing CNC parts with drill holes.

If you design holes that don't fit into these ranges, you may need specialized tooling to manufacture your parts.

Want to learn more about CNC machining?

Read our complete guide to CNC Machining

Standard metric drill bit sizes

Drill size Diameter (in)
0.05 mm0.0020
0.1 mm0.0039
0.2 mm0.0079
0.3 mm0.0118
0.4 mm0.0158
0.5 mm0.0197
0.6 mm0.0236
0.7 mm0.0276
0.8 mm0.0315
0.9 mm0.0354
1 mm0.0394
1.1 mm0.0433
1.2 mm0.0472
1.3 mm0.0512
1.4 mm0.0551
1.5 mm0.0591
1.6 mm0.0630
1.7 mm0.0669
1.8 mm0.0709
1.9 mm0.0748
2 mm0.0787
2.1 mm0.0827
2.2 mm0.0866
2.3 mm0.0906
2.4 mm0.0945
2.5 mm0.0984
2.6 mm0.1024
2.7 mm0.1063
2.8 mm0.1102
2.9 mm0.1142
3 mm0.1181
3.1 mm0.1221
3.2 mm0.1260
3.3 mm0.1299
3.4 mm0.1339
3.5 mm0.1378
3.6 mm0.1417
3.7 mm0.1457
3.8 mm0.1496
3.9 mm0.1535
4 mm0.1575
4.1 mm0.1614
4.2 mm0.1654
4.3 mm0.1693
4.4 mm0.1732
4.5 mm0.1772
4.6 mm0.1811
4.7 mm0.1850
4.8 mm0.1890
4.9 mm0.1929
5 mm0.1969
5.1 mm0.2008
5.2 mm0.2047
5.3 mm0.2087
5.4 mm0.2126
5.5 mm0.2165
5.6 mm0.2205
5.7 mm0.2244
5.8 mm0.2284
5.9 mm0.2323
6 mm0.2362
6.1 mm0.2402
6.2 mm0.2441
6.3 mm0.2480
6.4 mm0.2520
6.5 mm0.2559
6.6 mm0.2598
6.7 mm0.2638
6.8 mm0.2677
6.9 mm0.2717
7 mm0.2756
7.1 mm0.2795
7.2 mm0.2835
7.3 mm0.2874
7.4 mm0.2913
7.5 mm0.2953
7.6 mm0.2992
7.7 mm0.3032
7.8 mm0.3071
7.9 mm0.3110
8 mm0.3150
8.1 mm0.3189
8.2 mm0.3228
8.3 mm0.3268
8.4 mm0.3307
8.5 mm0.3347
8.6 mm0.3386
8.7 mm0.3425
8.8 mm0.3465
8.9 mm0.3504
9 mm0.3543
9.1 mm0.3583
9.2 mm0.3622
9.3 mm0.3661
9.4 mm0.3701
9.5 mm0.3740
9.6 mm0.3780
9.7 mm0.3819
9.8 mm0.3858
9.9 mm0.3898
10 mm0.3937
10.5 mm0.4134
11 mm0.4331
11.5 mm0.4528
12 mm0.4724
12.5 mm0.4921
13 mm0.5118
13.5 mm0.5315
14 mm0.5512
14.5 mm0.5709
15 mm0.5906
15.5 mm0.6102
16 mm0.6299
16.5 mm0.6496
17 mm0.6693
17.5 mm0.6890
18 mm0.7087
18.5 mm0.7284
19 mm0.7480
19.5 mm0.7677
20 mm0.7874
20.5 mm0.8071
21 mm0.8268
21.5 mm0.8465
22 mm0.8661
22.5 mm0.8858
23 mm0.9055
23.5 mm0.9252
24 mm0.9449
24.5 mm0.9646
25 mm0.9843
25.5 mm1.0039
26 mm1.0236
26.5 mm1.0433
27 mm1.0630
27.5 mm1.0827
28 mm1.1024
28.5 mm1.1221
29 mm1.1417
29.5 mm1.1614
30 mm1.1811
30.5 mm1.2008
31 mm1.2205
31.5 mm1.2402
32 mm1.2598
32.5 mm1.2795
33 mm1.2992
33.5 mm1.3189
34 mm1.3386
34.5 mm1.3583
35 mm1.3780
35.5 mm1.3976
36 mm1.4173
36.5 mm1.4370
37 mm1.4567
37.5 mm1.4764
38 mm1.4961

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Fractional inch drill bit sizes

Drill size Diameter (in) Diameter (mm)
1/64 in0.01560.3969
1/32 in0.03130.7938
3/64 in0.04691.1906
1/16 in0.06251.5875
5/64 in0.07811.9844
3/32 in0.09382.3813
7/64 in0.10942.7781
1/8 in0.12503.1750
9/64 in0.14063.5719
5/32 in0.15633.9688
11/64 in0.17194.3656
3/16 in0.18754.7625
13/64 in0.20315.1594
7/32 in0.21885.5563
15/64 in0.23445.9531
1/4 in0.25006.3500
17/64 in0.26566.7469
9/32 in0.28137.1438
19/64 in0.29697.5406
5/16 in0.31257.9375
21/64 in0.32818.3344
11/32 in0.34388.7313
23/64 in0.35949.1281
3/8 in0.37509.5250
25/64 in0.39069.9219
13/32 in0.406310.3188
27/64 in0.421910.7156
7/16 in0.437511.1125
29/64 in0.453111.5094
15/32 in0.468811.9063
31/64 in0.484412.3031
1/2 in0.500012.7000
33/64 in0.515613.0969
17/32 in0.531313.4938
35/64 in0.546913.8906
9/16 in0.562514.2875
37/64 in0.578114.6844
19/32 in0.593815.0813
39/64 in0.609415.4781
5/8 in0.625015.8750
41/64 in0.640616.2719
43/64 in0.671917.0656
11/16 in0.687517.4625
45/64 in0.703117.8594
23/32 in0.718818.2563
47/64 in0.734418.6531
3/4 in0.750019.0500
49/64 in0.765619.4469
25/32 in0.781319.8438
51/64 in0.796920.2406
13/16 in0.812520.6375
53/64 in0.828121.0344
27/32 in0.843821.4313
55/64 in0.859421.8281
7/8 in0.875022.2250
57/64 in0.890622.6219
29/32 in0.906323.0188
21/23 in0.913023.1913
59/64 in0.921923.4156
15/16 in0.937523.8125
61/64 in0.953124.2094
31/32 in0.968824.6063
63/64 in0.984425.0031
1 in1.000025.4000
1 1/64 in1.015625.7969
1 1/32 in1.031326.1938
1 3/64 in1.046926.5906
1 1/16 in1.062526.9875
1 5/64 in1.078127.3844
1 3/32 in1.093827.7813
1 7/64 in1.109428.1781
1 1/8 in1.125028.5750
1 9/64 in1.140628.9719
1 5/32 in1.156329.3688
1 11/64 in1.171929.7656
1 3/16 in1.187530.1625
1 13/64 in1.203130.5594
1 7/32 in1.218830.9563
1 15/64 in1.234431.3531
1 1/4 in1.250031.7500
1 17/64 in1.265632.1469
1 9/32 in1.281332.5438
1 19/64 in1.296932.9406
1 5/16 in1.312533.3375
1 21/64 in1.328133.7344
1 11/32 in1.343834.1313
1 23/64 in1.359434.5281
1 3/8 in1.375034.9250
1 25/64 in1.390635.3219
1 13/32 in1.406335.7188
1 27/64 in1.421936.1156
1 7/16 in1.437536.5125
1 29/64 in1.453136.9094
1 15/32 in1.468837.3063
1 31/64 in1.484437.7031
1 1/2 in1.500038.1000

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Wire gauge drill bit sizes

Drill size Diameter (in) Diameter (mm)
#1070.00190.0483
#1060.00230.0584
#1050.00270.0686
#1040.00310.0787
#1030.00350.0889
#1020.00390.0991
#1010.00430.1092
#1000.00470.1194
#990.00510.1295
#980.00550.1397
#970.00590.1499
#960.00630.1600
#950.00670.1702
#940.00710.1803
#930.00750.1905
#920.00790.2007
#910.00830.2108
#900.00870.2210
#890.00910.2311
#880.00950.2413
#870.01000.2540
#860.01050.2667
#850.01100.2794
#840.01150.2921
#830.01200.3048
#820.01250.3175
#810.01300.3302
#800.01350.3429
#790.01450.3680
#780.01600.4064
#770.01800.4572
#760.02000.5080
#750.02100.5334
#740.02250.5715
#730.02400.6096
#720.02500.6350
#710.02600.6604
#700.02800.7112
#690.02920.7417
#680.03100.7874
#670.03200.8128
#660.03300.8382
#650.03500.8890
#640.03600.9144
#630.03700.9398
#620.03800.9652
#610.03900.9906
#600.04001.0160
#590.04101.0414
#580.04201.0668
#570.04301.0922
#560.04651.1811
#550.05201.3208
#540.05501.3970
#530.05951.5113
#520.06351.6129
#510.06701.7018
#500.07001.7780
#490.07301.8542
#480.07601.9304
#470.07851.9939
#460.08102.0574
#450.08202.0828
#440.08602.1844
#430.08902.2606
#420.09352.3749
#410.09602.4384
#400.09802.4892
#390.09952.5273
#380.10152.5781
#370.10402.6416
#360.10652.7051
#350.11002.7940
#340.11102.8194
#330.11302.8702
#320.11602.9464
#310.12003.0480
#300.12853.2639
#290.13603.4544
#280.14053.5687
#270.14403.6576
#260.14703.7338
#250.14953.7973
#240.15203.8608
#230.15403.9116
#220.15703.9878
#210.15904.0386
#200.16104.0894
#190.16604.2164
#180.16954.3053
#170.17304.3942
#160.17704.4958
#150.18004.5720
#140.18204.6228
#130.18504.6990
#120.18904.8006
#110.19104.8514
#100.19354.9149
#90.19604.9784
#80.19905.0546
#70.20105.1054
#60.20405.1816
#50.20555.2197
#40.20905.3086
#30.21305.4102
#20.22105.6134
#10.22805.7912
A0.23405.9436
B0.23806.0452
C0.24206.1468
D0.24606.2484
E0.25006.3500
F0.25706.5278
G0.26106.6294
H0.26606.7564
I0.27206.9088
J0.27707.0358
K0.28107.1374
L0.29007.3660
M0.29507.4930
N0.30207.6708
O0.31608.0264
P0.32308.2042
Q0.33208.4328
R0.33908.6106
S0.34808.8392
T0.35809.0932
U0.36809.3472
V0.37709.5758
W0.38609.8044
X0.397010.0838
Y0.404010.2616
Z0.413010.4902

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