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Drill Bit Conversion Table

Numbered, fractional, and lettered drill bits are considered legacy units - depreciated.

Standard Drill Sizes Unless otherwise marked, dimensions are in inches. Cyan sizes are metric drills, Yellow sizes are numbered drills, Green sizes are fractional drills.
Size	Hole	Size	Hole	Size	Hole	Size	Hole	Size	Hole
0.10	.0040	0.80	.0315	#46	.0810	3.80	.1496	5.70	.2244
0.13	.0050	#67	.0320	#45	.0820	#24	.1520	5.75	.2264
0.15	.0059	#66	.0330	2.10	.0827	3.90	.1535	#1	.2280
#97	.0059	0.85	.0335	2.15	.0846	#23	.1540	5.80	.2283
#96	.0063	#65	.0350	#44	.0860	5/32	.1562	5.90	.2323
#95	.0067	0.90	.0354	2.20	.0866	#22	.1570	#A	.2340
#94	.0071	#64	.0360	2.25	.0886	4.00	.1575	15/64	.2344
#93	.0075	#63	.0370	#43	.0890	#21	.1590	6.00	.2362
#92	.0079	0.95	.0374	2.30	.0906	#20	.1610	#B	.2380
0.20	.0079	#62	.0380	2.35	.0295	4.10	.1614	6.10	.2402
#91	.0083	#61	.0390	#42	.0935	4.20	.1654	#C	.2420
#90	.0087	1.00	.0394	3/32	.0938	#19	.1660	6.20	.2441
0.22	.0087	#60	.0400	2.40	.0945	4.25	.1673	#D	.2460
#89	.0091	#59	.0410	#41	.0960	4.30	.1693	6.25	.2461
#88	.0095	1.05	.0413	2.45	.0965	#18	.1695	6.30	.2480
0.25	.0098	#58	.0420	#40	.0980	11/64	.1719	#E	.2500
#87	.0100	#57	.0430	2.50	.0984	#17	.1730	1/4	.2500
#86	.0105	1.10	.0433	#39	.0995	4.40	.1732	6.40	.2520
#85	.0110	1.15	.0453	#38	.1015	#16	.1770	6.50	.2559
0.28	.0110	#56	.0465	2.60	.1024	4.50	.1772	#F	.2570
#84	.0115	3/64	.0469	#37	.1040	#15	.1800	6.60	.2598
0.30	.0118	1.20	.0472	2.70	.1063	4.60	.1811	#G	.2610
#83	.0120	1.25	.0492	#36	.1065	#14	.1820	6.70	.2638
#82	.0125	1.30	.0512	2.75	.1083	#13	.1850	17/64	.2656
0.32	.0126	#55	.0520	7/64	.1094	4.70	.1850	6.75	.2657
#81	.0130	1.35	.0531	#35	.1100	4.75	.1870	#H	.2660
#80	.0135	#54	.0550	2.80	.1102	3/16	.1875	6.80	.2677
0.35	.0138	1.40	.0551	#34	.1110	4.80	.1890	6.90	.2717
#79	.0145	1.45	.0571	#33	.1130	#12	.1890	#I	.2720
1/64	.0156	1.50	.0591	2.90	.1142	#11	.1910	7.00	.2756
0.40	.0157	#53	.0595	#32	.1160	4.90	.1929	#J	.2770
#78	.0160	1.55	.0610	3.00	.1181	#10	.1935	7.10	.2795
0.45	.0177	1/16	.0625	#31	.1200	#9	.1960	#K	.2810
#77	.0180	1.60	.0630	3.10	.1220	5.00	.1969	9/32	.2812
0.50	.0197	#52	.0635	1/8	.1250	#8	.1990	7.20	.2835
#76	.0200	1.65	.0650	3.20	.1260	5.10	.2008	7.25	.2854
#75	.0210	1.70	.0669	3.15	.1280	#7	.2010	7.30	.2874
0.55	.0217	#51	.0670	#30	.1285	13/64	.2031	#L	.2900
#74	.0225	1.75	.0689	3.30	.1299	#6	.2040	7.40	.2913
0.60	.0236	#50	.0700	3.40	.1339	5.20	.2047	#M	.2950
#73	.0240	1.80	.0709	#29	.1360	#5	.2055	7.50	.2953
#72	.0250	1.85	.0728	3.50	.1378	5.25	.2067	19/64	.2969
0.65	.0256	#49	.0730	#28	.1405	5.30	.2087	7.60	.2992
#71	.0260	1.90	.0748	9/64	.1406	#4	.2090	#N	.3020
0.70	.0276	#48	.0760	3.60	.1417	5.40	.2126	7.70	.3031
#70	.0280	1.95	.0768	#27	.1440	#3	.2130	7.75	.3051
#69	.0292	5/64	.0781	3.70	.1457	5.50	.2165	7.8	.3071
0.75	.0295	#47	.0785	#26	.1470	7/32	.2188	7.90	.3110
#68	.0310	2.00	.0787	3.75	.1476	5.6	.2205	5/16	.3125
1/32	.0312	2.05	.0807	#25	.1495	#2	.2210
Note that the hole plating will make the finished hole size slightly less than the drill size - best to specified as "finished hole size"

gauge	inches	mm
80	0.0135	0.343
79	0.0145	0.368
78	0.016	0.406
77	0.018	0.457
76	0.020	0.508
75	0.021	0.533
74	0.0225	0.572
73	0.024	0.610
72	0.025	0.635
71	0.026	0.660
70	0.028	0.711
69	0.0292	0.742
68	0.031	0.787
67	0.032	0.813
66	0.033	0.838
65	0.035	0.889
64	0.036	0.914
63	0.037	0.940
62	0.038	0.965
61	0.039	0.991
60	0.040	1.016
59	0.041	1.041
58	0.042	1.067
57	0.043	1.092
56	0.0465	1.181
55	0.052	1.321
54	0.055	1.397
53	0.0595	1.511
52	0.0635	1.613
51	0.067	1.702
50	0.070	1.778
49	0.073	1.854
48	0.076	1.930
47	0.0785	1.994
46	0.081	2.057
45	0.082	2.083
44	0.086	2.184
43	0.089	2.261
42	0.0935	2.375
41	0.096	2.438
40	0.098	2.489
39	0.0995	2.527
38	0.1015	2.578
37	0.104	2.642
36	0.1065	2.705
35	0.110	2.794
34	0.111	2.819
33	0.113	2.870
32	0.116	2.946
31	0.120	3.048
30	0.1285	3.264
29	0.136	3.454
28	0.1405	3.569
27	0.144	3.658
26	0.147	3.734
25	0.1495	3.797
24	0.152	3.861
23	0.154	3.912
22	0.157	3.988
21	0.159	4.039
20	0.161	4.089
19	0.166	4.216
18	0.1695	4.305
17	0.173	4.394
16	0.177	4.496
15	0.180	4.572
14	0.182	4.623
13	0.185	4.699
12	0.189	4.801
11	0.191	4.851
10	0.1935	4.915
9	0.196	4.978
8	0.199	5.055
7	0.201	5.105
6	0.204	5.182
5	0.2055	5.220
4	0.209	5.309
3	0.213	5.410
2	0.221	5.613
1	0.228	5.791
A	0.234	5.944
B	0.238	6.045
C	0.242	6.147
D	0.246	6.248
E	0.250	6.350
F	0.257	6.528
G	0.261	6.629
H	0.266	6.756
I	0.272	6.909
J	0.277	7.036
K	0.281	7.137
L	0.290	7.366
M	0.295	7.493
N	0.302	7.671
O	0.316	8.026
P	0.323	8.204
Q	0.332	8.433
R	0.339	8.611
S	0.348	8.839
T	0.358	9.093
U	0.368	9.347
V	0.377	9.576
W	0.386	9.804
X	0.397	10.08
Y	0.404	10.26
Z	0.413	10.49

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