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Drill Letter and Number Decimal Cross Reference

Decimal Sizes for Numbered and Lettered Drills

Drill Number / Decimal Cross Reference

drill number	decimal (inch)	decimal (mm)
97	.0059	.150
96	.0063	.160
95	.0067	.170
94	.0071	.180
93	.0075	.190
92	.0079	.200
91	.0083	.211
90	.0087	.221
89	.0091	.231
88	.0095	.241
87	.0100	.254
86	.0105	.267
85	.0110	.280
84	.0115	.292
83	.0120	.305
82	.0125	.318
81	.0130	.330
80	.0135	.343
79	.0145	.368
78	.0160	.406
77	.0180	.457
76	.0200	.508
75	.0210	.533
74	.0225	.572
73	.0240	.610
72	.0250	.635
71	.0260	.660
70	.0280	.711
69	.0292	.742
68	.0310	.787
67	.0320	.813
66	.0330	.838
65	.0350	.889
64	.0360	.914
63	.0370	.940
62	.0380	.965
61	.0390	.991
60	.0400	1.016
59	.0410	1.041
58	.0420	1.067
57	.0430	1.092
56	.0465	1.181
55	.0520	1.321
54	.0550	1.397
53	.0595	1.511
52	.0635	1.613
51	.0670	1.702
50	.0700	1.778
49	.0730	1.854
48	.0760	1.930
47	.0785	1.994
46	.0810	2.057
45	.0820	2.083
44	.0860	2.184
43	.0890	2.261
42	.0935	2.375
41	.0960	2.438
40	.0980	2.489
39	.0995	2.527
38	.1015	2.578
37	.1040	2.642
36	.1065	2.705
35	.1100	2.794
34	.1110	2.819
33	.1130	2.870
32	.1160	2.946
31	.1200	3.048
30	.1285	3.264
29	.1360	3.454
28	.1405	3.569
27	.1440	3.658
26	.1470	3.734
25	.1495	3.797
24	.1520	3.861
23	.1540	3.912
22	.1570	3.988
21	.1590	4.039
20	.1610	4.089
19	.1660	4.216
18	.1695	4.305
17	.1730	4.394
16	.1770	4.496
15	.1800	4.572
14	.1820	4.623
13	.1850	4.700
12	.1890	4.800
11	.1910	4.851
10	.1935	4.915
9	.1960	4.978
8	.1990	5.054
7	.2010	5.105
6	.2040	5.182
5	.2055	5.220
4	.2090	5.309
3	.2130	5.410
2	.2210	5.613
1	.2280	5.791

Drill Letter / Decimal Cross Reference

drill letter	decimal (inch)	decimal (mm)
A	.2340	5.944
B	.2380	6.045
C	.242	6.147
D	.2460	6.248
E	.2500	6.350
F	.2570	6.528
G	.2610	6.629
H	.2660	6.756
I	.2720	6.909
J	.2770	7.036
K	.2810	7.137
L	.2900	7.366
M	.2950	7.493
N	.3020	7.671
O	.3160	8.026
P	.3230	8.204
Q	.3320	8.433
R	.3390	8.611
S	.3480	8.839
T	.3580	9.093
U	.3680	9.347
V	.3770	9.576
W	.3860	9.804
X	.3970	10.084
Y	.4040	10.262
Z	.4130	10.490