| Drill Chart - ANSI & ISO Sizes (See typical tolerances of drilled holes at bottom of page) View in PDF Format: 8½x11" or 11x17" sizes. |
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| ANSI Size Drills | ISO ("Metric") Size Drills and Conversion to Inches | |||||||||||
| ANSI Size |
Decimal | ANSI Size |
Decimal | ANSI Size |
Decimal | ISO Size |
Decimal (in.) |
ISO Size |
Decimal (in.) |
ISO Size |
Decimal (in.) |
|
| 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 |
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| 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 |
| 0.0135 — 0.125" | +.004 / -.001" | |
| 0.1260 — 0.250" | +.005 / -.001" | |
| 0.2510 — 0.500" | +.006 / -.001" | |
| 0.5010 — 0.750" | +0.008 / -0.001" | |
| 0.7510 — 1.000" | +0.010 / -0.001" | |
| 1 .001 — 2.000" | +0.012 / -0.001" | |