Drill Bit Size Charts for CNC Machining

Using standard drill bit sizes is a great way to keep manufacturing costs down, as custom tooling can quickly become expensive. Here, we present three conversion tables for standard drill bit sizes in metric, fractional inch, and wire gauge measurements. These are commonly used in CNC machining and can help you save money by avoiding the need for custom tooling.

Drilling

Why Use Standard Drill Bit Sizes?

Custom tooling can drive up your manufacturing costs significantly. By optimizing the use of standard tooling, you can save a considerable amount of money when producing custom parts. To assist you, we’ve compiled three tables summarizing the standard drill bit sizes used in CNC machining.

Drill Bit Size Charts

Below, you’ll find tables for metric, fractional inch, and wire gauge drill bit sizes. It’s beneficial, and often crucial, to align your designs with these standard sizes when planning CNC parts with drill holes. If your design includes holes that fall outside these ranges, you might need specialized tooling to manufacture your parts. Using these charts can help you stay within the standard sizes, reducing the need for custom solutions and keeping your production costs lower.

Standard Metric Drill Bit Sizes (Descending Order)

Drill Size Diameter (in)
38 mm 1.4961
37.5 mm 1.4764
37 mm 1.4567
36.5 mm 1.4370
36 mm 1.4173
35.5 mm 1.3976
35 mm 1.3780
34.5 mm 1.3583
34 mm 1.3386
33.5 mm 1.3189
33 mm 1.2992
32.5 mm 1.2795
32 mm 1.2598
31.5 mm 1.2402
31 mm 1.2205
30.5 mm 1.2008
30 mm 1.1811
29.5 mm 1.1614
29 mm 1.1417
28.5 mm 1.1221
28 mm 1.1024
27.5 mm 1.0827
27 mm 1.0630
26.5 mm 1.0433
26 mm 1.0236
25.5 mm 1.0039
25 mm 0.9843
24.5 mm 0.9646
24 mm 0.9449
23.5 mm 0.9252
23 mm 0.9055
22.5 mm 0.8858
22 mm 0.8661
21.5 mm 0.8465
21 mm 0.8268
20.5 mm 0.8071
20 mm 0.7874
19.5 mm 0.7677
19 mm 0.7480
18.5 mm 0.7284
18 mm 0.7087
17.5 mm 0.6890
17 mm 0.6693
16.5 mm 0.6496
16 mm 0.6299
15.5 mm 0.6102
15 mm 0.5906
14.5 mm 0.5709
14 mm 0.5512
13.5 mm 0.5315
13 mm 0.5118
12.5 mm 0.4921
12 mm 0.4724
11.5 mm 0.4528
11 mm 0.4331
10.5 mm 0.4134
10 mm 0.3937
9.9 mm 0.3898
9.8 mm 0.3858
9.7 mm 0.3819
9.6 mm 0.3780
9.5 mm 0.3740
9.4 mm 0.3701
9.3 mm 0.3661
9.2 mm 0.3622
9.1 mm 0.3583
9 mm 0.3543
8.9 mm 0.3504
8.8 mm 0.3465
8.7 mm 0.3425
8.6 mm 0.3386
8.5 mm 0.3347
8.4 mm 0.3307
8.3 mm 0.3268
8.2 mm 0.3228
8.1 mm 0.3189
8 mm 0.3150
7.9 mm 0.3110
7.8 mm 0.3071
7.7 mm 0.3032
7.6 mm 0.2992
7.5 mm 0.2953
7.4 mm 0.2913
7.3 mm 0.2874
7.2 mm 0.2835
7.1 mm 0.2795
7 mm 0.2756
6.9 mm 0.2717
6.8 mm 0.2677
6.7 mm 0.2638
6.6 mm 0.2598
6.5 mm 0.2559
6.4 mm 0.2520
6.3 mm 0.2480
6.2 mm 0.2441
6.1 mm 0.2402
6 mm 0.2362
5.9 mm 0.2323
5.8 mm 0.2284
5.7 mm 0.2244
5.6 mm 0.2205
5.5 mm 0.2165
5.4 mm 0.2126
5.3 mm 0.2087
5.2 mm 0.2047
5.1 mm 0.2008
5 mm 0.1969
4.9 mm 0.1929
4.8 mm 0.1890
4.7 mm 0.1850
4.6 mm 0.1811
4.5 mm 0.1772
4.4 mm 0.1732
4.3 mm 0.1693
4.2 mm 0.1654
4.1 mm 0.1614
4 mm 0.1575
3.9 mm 0.1535
3.8 mm 0.1496
3.7 mm 0.1457
3.6 mm 0.1417
3.5 mm 0.1378
3.4 mm 0.1339
3.3 mm 0.1299
3.2 mm 0.1260
3.1 mm 0.1221
3 mm 0.1181
2.9 mm 0.1142
2.8 mm 0.1102
2.7 mm 0.1063
2.6 mm 0.1024
2.5 mm 0.0984
2.4 mm 0.0945
2.3 mm 0.0906
2.2 mm 0.0866
2.1 mm 0.0827
2 mm 0.0787
1.9 mm 0.0748
1.8 mm 0.0709
1.7 mm 0.0669
1.6 mm 0.0630
1.5 mm 0.0591
1.4 mm 0.0551
1.3 mm 0.0512
1.2 mm 0.0472
1.1 mm 0.0433
1 mm 0.0394
0.9 mm 0.0354
0.8 mm 0.0315
0.7 mm 0.0276
0.6 mm 0.0236
0.5 mm 0.0197
0.4 mm 0.0158
0.3 mm 0.0118
0.2 mm 0.0079
0.1 mm 0.0039
0.05 mm 0.0020

Fractional Inch Drill Bit Sizes (Descending Order)

Drill Size Diameter (in) Diameter (mm)
1 1/2 in 1.5000 38.1000
1 31/64 in 1.4844 37.7031
1 15/32 in 1.4688 37.3063
1 29/64 in 1.4531 36.9094
1 7/16 in 1.4375 36.5125
1 27/64 in 1.4219 36.1156
1 13/32 in 1.4063 35.7188
1 25/64 in 1.3906 35.3219
1 3/8 in 1.3750 34.9250
1 23/64 in 1.3594 34.5281
1 11/32 in 1.3438 34.1313
1 21/64 in 1.3281 33.7344
1 5/16 in 1.3125 33.3375
1 19/64 in 1.2969 32.9406
1 9/32 in 1.2813 32.5438
1 17/64 in 1.2656 32.1469
1 1/4 in 1.2500 31.7500
1 15/64 in 1.2344 31.3531
1 7/32 in 1.2188 30.9563
1 13/64 in 1.2031 30.5594
1 3/16 in 1.1875 30.1625
1 11/64 in 1.1719 29.7656
1 5/32 in 1.1563 29.3688
1 9/64 in 1.1406 28.9719
1 1/8 in 1.1250 28.5750
1 7/64 in 1.1094 28.1781
1 3/32 in 1.0938 27.7813
1 5/64 in 1.0781 27.3844
1 1/16 in 1.0625 26.9875
1 3/64 in 1.0469 26.5906
1 1/32 in 1.0313 26.1938
1 1/64 in 1.0156 25.7969
1 in 1.0000 25.4000
63/64 in 0.9844 25.0031
31/32 in 0.9688 24.6063
61/64 in 0.9531 24.2094
15/16 in 0.9375 23.8125
59/64 in 0.9219 23.4156
21/23 in 0.9130 23.1913
29/32 in 0.9063 23.0188
57/64 in 0.8906 22.6219
7/8 in 0.8750 22.2250
55/64 in 0.8594 21.8281
27/32 in 0.8438 21.4313
53/64 in 0.8281 21.0344
13/16 in 0.8125 20.6375
51/64 in 0.7969 20.2406
25/32 in 0.7813 19.8438
49/64 in 0.7656 19.4469
3/4 in 0.7500 19.0500
47/64 in 0.7344 18.6531
23/32 in 0.7188 18.2563
45/64 in 0.7031 17.8594
11/16 in 0.6875 17.4625
43/64 in 0.6719 17.0656
41/64 in 0.6563 16.2719
5/8 in 0.6250 15.8750
39/64 in 0.6094 15.4781
19/32 in 0.5938 15.0813
37/64 in 0.5781 14.6844
9/16 in 0.5625 14.2875
35/64 in 0.5469 13.8906
17/32 in 0.5313 13.4938
33/64 in 0.5156 13.0969
1/2 in 0.5000 12.7000
31/64 in 0.4844 12.3031
15/32 in 0.4688 11.9063
29/64 in 0.4531 11.5094
7/16 in 0.4375 11.1125
27/64 in 0.4219 10.7156
13/32 in 0.4063 10.3188
25/64 in 0.3906 9.9219
3/8 in 0.3750 9.5250
23/64 in 0.3594 9.1281
11/32 in 0.3438 8.7313
21/64 in 0.3281 8.3344
5/16 in 0.3125 7.9375
19/64 in 0.2969 7.5406
9/32 in 0.2813 7.1438
17/64 in 0.2656 6.7469
1/4 in 0.2500 6.3500
15/64 in 0.2344 5.9531
7/32 in 0.2188 5.5563
13/64 in 0.2031 5.1594
3/16 in 0.1875 4.7625
11/64 in 0.1719 4.3656
5/32 in 0.1563 3.9688
9/64 in 0.1406 3.5719
1/8 in 0.1250

Wire Gauge Drill Bit Sizes (Descending Order)

Drill Size Diameter (mm) Diameter (in)
Z 10.4902 0.4130
Y 10.2616 0.4040
X 10.0838 0.3970
W 9.8044 0.3860
V 9.5758 0.3770
U 9.3472 0.3680
T 9.0932 0.3580
S 8.8392 0.3480
R 8.6106 0.3390
Q 8.4328 0.3320
P 8.2042 0.3230
O 8.0264 0.3160
N 7.6708 0.3020
M 7.4930 0.2950
L 7.3660 0.2900
K 7.1374 0.2810
J 7.0358 0.2770
I 6.9088 0.2720
H 6.7564 0.2660
G 6.6294 0.2610
F 6.5278 0.2570
E 6.3500 0.2500
D 6.2484 0.2460
C 6.1468 0.2420
B 6.0452 0.2380
A 5.9436 0.2340
1 5.7912 0.2280
2 5.6134 0.2210
3 5.4102 0.2130
4 5.3086 0.2090
5 5.2197 0.2055
6 5.1816 0.2040
7 5.1054 0.2010
8 5.0546 0.1990
9 4.9784 0.1960
10 4.9149 0.1935
11 4.8514 0.1910
12 4.8006 0.1890
13 4.6990 0.1850
14 4.6228 0.1820
15 4.5720 0.1800
16 4.4958 0.1770
17 4.3942 0.1730
18 4.3053 0.1695
19 4.2164 0.1660
20 4.0894 0.1610
21 4.0386 0.1590
22 3.9878 0.1570
23 3.9116 0.1540
24 3.8608 0.1520
25 3.7973 0.1495
26 3.7338 0.1470
27 3.6576 0.1440
28 3.5687 0.1405
29 3.4544 0.1360
30 3.2639 0.1285
31 3.0480 0.1200
32 2.9464 0.1160
33 2.8702 0.1130
34 2.8194 0.1110
35 2.7940 0.1100
36 2.7051 0.1065
37 2.6416 0.1040
38 2.5781 0.1015
39 2.5273 0.0995
40 2.4892 0.0980
41 2.4384 0.0960
42 2.3749 0.0935
43 2.2606 0.0890
44 2.1844 0.0860
45 2.0828 0.0820
46 2.0574 0.0810
47 1.9939 0.0785
48 1.9304 0.0760
49 1.8542 0.0730
50 1.7780 0.0700
51 1.7018 0.0670
52 1.6129 0.0635
53 1.5113 0.0595
54 1.3970 0.0550
55 1.3208 0.0520
56 1.1811 0.0465
57 1.0922 0.0430
58 1.0668 0.0420
59 1.0414 0.0410
60 1.0160 0.0400
61 0.9906 0.0390
62 0.9652 0.0380
63 0.9398 0.0370
64 0.9144 0.0360
65 0.8890 0.0350
66 0.8382 0.0330
67 0.8128 0.0320
68 0.7874 0.0310
69 0.7417 0.0292
70 0.7112 0.0280
71 0.6604 0.0260
72 0.6350 0.0250
73 0.6096 0.0240
74 0.5715 0.0225
75 0.5334 0.0210
76 0.5080 0.0200
77 0.4572 0.0180
78 0.4064 0.0160
79 0.3680 0.0145
80 0.3429 0.0135
81 0.3302 0.0130
82 0.3175 0.0125
83 0.3048 0.0120
84 0.2921 0.0115
85 0.2794 0.0110
86 0.2667 0.0105
87 0.2540 0.0100
88 0.2413 0.0095
89 0.2311 0.0091
90 0.2210 0.0087
91 0.2108 0.0083
92 0.2007 0.0079
93 0.1905 0.0075
94 0.1803 0.0071
95 0.1702 0.0067
96 0.1600 0.0063
97 0.1499 0.0059
98 0.1397 0.0055
99 0.1295 0.0051
100 0.1194 0.0047
101 0.1092 0.0043
102 0.0991 0.0039
103 0.0889 0.0035
104 0.0787 0.0031
105 0.0686 0.0027
106 0.0584 0.0023
107 0.0483 0.0019
0 replies

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published.