Machinist Drill Sizes - ANSI Drill Sizes / ISO Metric Drill Sizes
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(See typical tolerances of drilled holes at bottom of
page )
ANSI Size Drills
ISO (Metric Size Drills) and
Conversion to Inches
Drill Decimal Drill Decimal Drill Decimal Drill Decimal Drill Decimal Drill Decimal
80 .0135 1/8 .1250 O .3160 .35 .0138 3.4 .1339 8.0 .3150
79 .0145 30 .1285 P .3230 .4 .0157 3.5 .1378 8.1 .3189
1/64 .0156 29 .1360 21/64 .3281 .45 .0177 3.6 .1417 8.2 .3228
78 .0160 28 .1405 Q .3320 .5 .0197 3.7 .1457 8.25 .3248
77 .0180 9/64 .1406 R .3390 .55 .0217 3.75 .1477 8.3 .3267
76 .0200 27 .1440 11/32 .3437 .6 .0236 3.8 .1496 8.4 .3307
75 .0210 26 .1470 S .3480 .65 .0256 3.9 .1535 8.5 .3346
74 .0225 25 .1495 T .3580 .7 .0276 4.0 .1575 8.6 .3386
73 .0240 24 .1520 23/64 .3594 .75 .0295 4.1 .1614 8.7 .3425
72 .0250 23 .1540 U .3680 .8 .0315 4.2 .1654 8.75 .3445
71 .0260 5/32 .1562 3/8 .3750 .85 .0335 4.25 .1674 8.8 .3465
70 .0280 22 .1570 V .3770 .9
.0355 4.3 .1693 8.9 .3504
69 .0292 21 .1590 W .3860 .95 .0374 4.4 .1732 9.0 .3543
68 .0310 20 .1610 25/64 .3906 1.0 .0394 4.5 .1771 9.1 .3583
1/32 .0313 19 .1660 X .3970 1.05 .0413 4.6 .1811 9.2 .3622
67 .0320 18 .1695 Y .4040
1.1 .0433 4.7 .1850 9.25 .3642
66 .0330 11/64 .1719 13/32 .4062 1.15 .0453 4.75 .1870 9.35 .3661
65 .0350 17 .1730 Z .4130 1.2 .0472 4.8 .1890 9.4 .3701
64 .0360 16 .1770 27/64 .4219 1.25 .0492 4.9 .1929 9.5 .3740
63 .0370 15 .1800 7/16 .4375 1.3 .0512 5.0 .1968 9.6 .3780
62 .0380 14 .1820 29/64 .4531 1.35 .0531 5.1 .2008 9.7 .3819
61 .0390 13 .1850 15/32 .4687 1.4 .0551 5.2 .2047 9.75 .3839
60 .0400 3/16 .1875 31/64 .4844 1.45 .0571 5.25 .2067 9.8 .3858
59 .0410 12 .1890 ½ .5000 1.5 .0591 5.3 .2087 9.9 .3898
58 .0420 11 .1910 33/64 .5156 1.55 .0610 5.4 .2126 10.0 .3937
57 .0430 10 .1935 17/32 .5312 1.6 .0629 5.5 .2165 10.5 .4133
56 .0465 9 .1960 35/64 .5469 1.65 .0650 5.6 .2205 11.0 .4331
3/64 .0469 8 .1990 9/16 .5625 1.7 .0669 5.7 .2244 11.5 .4528
55 .0520 7 .2010 37/64 .5781 1.75 .0689 5.75 .2264 12.0 .4724
54 .0550 13/64 .2031 19/32 .5937 1.8 .0709 5.8 .2283 12.5 .4921
53 .0595 6 .2040 39/64 .6094 1.85 .0728 5.9 .2323 13.0 .5118
1/16 .0625 5 .2055 5/8 .6250 1.9 .0748 6.0 .2362 13.5 .5315
52 .0635 4 .2090 41/64 .6406 1.95 .0768 6.1 .2401 14.0 .5512
51 .0670 3 .2130 21/32 .6562 2.0 .0787 6.2 .2441 14.5 .5708
50 .0700 7/32 .2187 43/64 .6719 2.05 .0807 6.25 .2461 15.0 .5906
49 .0730 2 .2210 11/16 .6875 2.1 .0827 6.3 .2480 15.5 .6102
48 .0760 1 .2280 45/64 .7031 2.15 .0846 6.4 .2520 16.0 .6300
5/64 .0781 A .2340 23/32 .7187 2.2 .0866 6.5 .2559 16.5 .6496
47 .0785 15/64 .2344 47/64 .7344 2.25 .0886 6.6 .2598 17.0 .6693
46 .0810 B .2380 ¾ .7500 2.3 .0905 6.7 .2638 17.5 .6889
45 .0820 C .2420 49/64 .7656 2.35 .0925 6.75 .2658 18.0 .7087
44 .0860 D .2460 25/32 .7812 2.4 .0945 6.8 .2677 18.5 .7283
43 .0890 E .2500 51/64 .7969 2.45 .0965 6.9 .2716 19.0 .7480
42 .0935 ¼ .2500 13/16 .8125 2.5 .0984 7.0 .2756 19.5 .7677
3/32 .0937 F .2570 53/64 .8281 2.55 .1004 7.1 .2795 20.0 .7874
41 .0960 G .2610 27/32 .8437 2.6 .1024 7.2 .2835 20.5 .8071
40 .0980 17/64 .2656 55/64 .8594 2.65 .1043 7.25 .2855 21.0 .8268
39 .0995 H .2660 7/8 .8750 2.7 .1063 7.3 .2874 21.5 .8465
38 .1015 I .2720 57/64 .8906 2.75 .1083 7.4 .2913 22.0 .8661
37 .1040 J .2770 29/32 .9062 2.8 .1102 7.5 .2953 22.5 .8858
36 .1065 K .2811 59/64 .9219 2.9 .1142 7.6 .2990 23.0 .9055
7/64 .1093 9/32 .2812 15/16 .9375 3.0 .1181 7.7 .3031 23.5 .9252
35 .1100 L .2900 61/64 .9531 3.1 .1220 7.75 .3051 24.0 .9449
34 .1110 M .2950 31/32 .9687 3.2 .1260 7.8 .3071 24.5 .9646
33 .1130 19/64 .2968 63/64 .9844 3.25 .1280 7.9 .3110 25.0 .9843
32 .1160 N .3020 1 1.000 3.3 .1299
31 .1200 5/16 .3125
HOLE DIAMETER TOLERANCE-STANDARD
DRILLED HOLE TOLERANCES
These size and
tolerance are for holes drilled with a drilling machine using suitable
jigs and fixtures. The hole tolerances depend upon the diameter of the
hole and increase as the hole size increases. The following are standard
tolerances for general machine work and apply in all cases except where
greater or lesser accuracy is required by the design.
Drilled Hole Size
Tolerance
.0135 THRU .125
+.004/ -.001
.1260 THRU .250
+.005/ -.001
.2510 THRU .500
+.006/-.001
.5010 THRU .750
+.008/ -.001
.7510 THRU 1.000
+.010/ -.001
1 .001 THRU 2.000
+.012/ -.001
