GMT CNC Machining Feeds and Speeds Calculator
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GMT Tap Drill Chart
Tap Drill Reference Chart
Aluminum, Brass & Plastics 75% Thread | Stainless Steel, Steels & Iron 50% Thread | Clearance Hole Drills - Close Fit | Clearance Hole Drills - Free Fit | ||||||||
No. or Dia. | # Threads Per Inch | Minor Diameter | Major Diameter | Drill Size | Decimal Equiv. | Drill Size | Decimal Equiv. | Drill Size | Decimal Equiv. | Drill Size | Decimal Equiv. |
0 | 80 | 0.0447 | 0.0600 | 3/64 | 0.0469 | 55 | 0.0520 | 52 | 0.0635 | 50 | 0.0700 |
1 | 64 | 0.0538 | 0.0730 | 53 | 0.0595 | 1/16 | 0.0625 | 48 | 0.0760 | 46 | 0.0810 |
1 | 72 | 0.0560 | 0.0730 | 53 | 0.0595 | 52 | 0.0635 | 48 | 0.0760 | 46 | 0.0810 |
2 | 56 | 0.0641 | 0.0860 | 50 | 0.0700 | 49 | 0.0730 | 43 | 0.0890 | 41 | 0.0960 |
2 | 64 | 0.0668 | 0.0860 | 50 | 0.0700 | 48 | 0.0760 | 43 | 0.0890 | 41 | 0.0960 |
3 | 48 | 0.0734 | 0.0990 | 47 | 0.0785 | 44 | 0.0860 | 37 | 0.1040 | 35 | 0.1100 |
3 | 56 | 0.0771 | 0.0990 | 45 | 0.0820 | 43 | 0.0890 | 37 | 0.1040 | 35 | 0.1100 |
4 | 40 | 0.0813 | 0.1120 | 43 | 0.0890 | 41 | 0.0960 | 32 | 0.1160 | 30 | 0.1285 |
4 | 48 | 0.0864 | 0.1120 | 42 | 0.0935 | 40 | 0.0980 | 32 | 0.1160 | 30 | 0.1285 |
5 | 40 | 0.0943 | 0.1250 | 38 | 0.1015 | 7/64 | 0.1094 | 30 | 0.1285 | 29 | 0.1360 |
5 | 44 | 0.0971 | 0.1250 | 37 | 0.1040 | 35 | 0.1100 | 30 | 0.1285 | 29 | 0.1360 |
6 | 32 | 0.0997 | 0.1380 | 36 | 0.1065 | 32 | 0.1160 | 27 | 0.1440 | 25 | 0.1495 |
6 | 40 | 0.1073 | 0.1380 | 33 | 0.1130 | 31 | 0.1200 | 27 | 0.1440 | 25 | 0.1495 |
8 | 32 | 0.1257 | 0.1640 | 29 | 0.1360 | 27 | 0.1440 | 18 | 0.1695 | 16 | 0.1770 |
8 | 36 | 0.1299 | 0.1640 | 29 | 0.1360 | 26 | 0.1470 | 18 | 0.1695 | 16 | 0.1770 |
10 | 24 | 0.1389 | 0.1900 | 25 | 0.1495 | 20 | 0.1610 | 9 | 0.1960 | 7 | 0.2010 |
10 | 32 | 0.1517 | 0.1900 | 21 | 0.1590 | 18 | 0.1695 | 9 | 0.1960 | 7 | 0.2010 |
12 | 24 | 0.1649 | 0.2160 | 16 | 0.1770 | 12 | 0.1890 | 2 | 0.2210 | 1 | 0.2280 |
12 | 28 | 0.1722 | 0.2160 | 14 | 0.1820 | 10 | 0.1935 | 2 | 0.2210 | 1 | 0.2280 |
12 | 32 | 0.1777 | 0.2160 | 13 | 0.1850 | 9 | 0.1960 | 2 | 0.2210 | 1 | 0.2280 |
1/4 | 20 | 0.1887 | 0.2500 | 7 | 0.2010 | 7/32 | 0.2188 | F | 0.2570 | H | 0.2660 |
1/4 | 28 | 0.2062 | 0.2500 | 3 | 0.2130 | 1 | 0.2280 | F | 0.2570 | H | 0.2660 |
1/4 | 32 | 0.2117 | 0.2500 | 7/32 | 0.2188 | 1 | 0.2280 | F | 0.2570 | H | 0.2660 |
5/16 | 18 | 0.2443 | 0.3125 | F | 0.2570 | J | 0.2770 | P | 0.3230 | Q | 0.3320 |
5/16 | 24 | 0.2614 | 0.3125 | I | 0.2720 | 9/32 | 0.2812 | P | 0.3230 | Q | 0.3320 |
5/16 | 32 | 0.2742 | 0.3125 | 9/32 | 0.2812 | L | 0.2900 | P | 2.3230 | Q | 0.3320 |
3/8 | 16 | 0.2983 | 0.3750 | 5/16 | 0.3125 | Q | 0.3320 | W | 0.3860 | X | 0.3970 |
3/8 | 24 | 0.3239 | 0.3750 | Q | 0.3320 | S | 0.3480 | W | 0.3860 | X | 0.3970 |
3/8 | 32 | 0.3367 | 0.3750 | 11/32 | 0.3438 | T | 0.3580 | W | 0.3860 | X | 0.3970 |
7/16 | 14 | 0.3499 | 0.4375 | U | 0.3680 | 25/64 | 0.3906 | 29/64 | 0.4531 | 15/32 | 0.4687 |
7/16 | 20 | 0.3762 | 0.4375 | 25/64 | 0.3906 | 13/32 | 0.4062 | 29/64 | 0.4531 | 15/32 | 0.4687 |
7/16 | 28 | 0.3937 | 0.4375 | Y | 0.4040 | Z | 0.4130 | 29/64 | 0.4531 | 15/32 | 0.4687 |
1/2 | 13 | 0.4056 | 0.5000 | 27/64 | 0.4219 | 29/64 | 0.4531 | 33/64 | 0.5156 | 17/32 | 0.5312 |
1/2 | 20 | 0.4386 | 0.5000 | 29/64 | 0.4531 | 15/32 | 0.4688 | 33/64 | 0.5156 | 17/32 | 0.5312 |
1/2 | 28 | 0.4562 | 0.5000 | 15/32 | 0.4688 | 15/32 | 0.4688 | 33/64 | 0.5156 | 17/32 | 0.5312 |
9/16 | 12 | 0.4603 | 0.5625 | 31/64 | 0.4844 | 33/64 | 0.5156 | 37/64 | 0.5781 | 19/32 | 0.5938 |
9/16 | 18 | 0.4943 | 0.5625 | 33/64 | 0.5156 | 17/32 | 0.5312 | 37/64 | 0.5781 | 19/32 | 0.5938 |
9/16 | 24 | 0.5114 | 0.5625 | 33/64 | 0.5156 | 17/32 | 0.5312 | 37/64 | 0.5781 | 19/32 | 0.5938 |
5/8 | 11 | 0.5135 | 0.6250 | 17/32 | 0.5312 | 9/16 | 0.5625 | 41/64 | 0.6406 | 21/32 | 0.6562 |
5/8 | 18 | 0.5568 | 0.6250 | 37/64 | 0.5781 | 19/32 | 0.5938 | 41/64 | 0.6406 | 21/32 | 0.6562 |
5/8 | 24 | 0.5739 | 0.6250 | 37/64 | 0.5781 | 19/32 | 0.5938 | 41/64 | 0.6406 | 21/32 | 0.6562 |
11/16 | 24 | 0.6364 | 0.6875 | 41/64 | 0.6406 | 21/32 | 0.6562 | 45/64 | 0.7031 | 23/32 | 0.7188 |
3/4 | 10 | 0.6273 | 0.7500 | 21/32 | 0.6562 | 11/16 | 0.6875 | 49/64 | 0.7656 | 25/32 | 0.7812 |
3/4 | 16 | 0.6733 | 0.7500 | 11/16 | 0.6875 | 45/64 | 0.7031 | 49/64 | 0.7656 | 25/32 | 0.7812 |
3/4 | 20 | 0.6887 | 0.7500 | 45/64 | 0.7031 | 23/32 | 0.7188 | 49/64 | 0.7656 | 25/32 | 0.7812 |
13/16 | 20 | 0.7512 | 0.8125 | 49/64 | 0.7656 | 25/32 | 0.7812 | 53/64 | 0.8281 | 27/32 | 0.8438 |
7/8 | 9 | 0.7387 | 0.8750 | 49/64 | 0.7656 | 51/64 | 0.7969 | 57/64 | 0.8906 | 29/32 | 0.9062 |
7/8 | 14 | 0.7874 | 0.8750 | 13/16 | 0.8125 | 53/64 | 0.8281 | 57/64 | 0.8906 | 29/34 | 0.9062 |
7/8 | 20 | 0.8137 | 0.8750 | 53/64 | 0.8281 | 27/32 | 0.8438 | 57/64 | 0.8906 | 29/32 | 0.9062 |
15/16 | 20 | 0.8762 | 0.9375 | 57/64 | 0.8906 | 29/32 | 0.9062 | 61/64 | 0.9531 | 31/32 | 0.9688 |
1 | 8 | 0.8466 | 1.000 | 7/8 | 0.8750 | 59/64 | 0.9219 | 1-1/64 | 1.0156 | 1-1/32 | 1.0313 |
1 | 12 | 0.8978 | 1.000 | 15/16 | 0.9375 | 61/64 | 0.9531 | 1-1/64 | 1.0156 | 1-1/32 | 1.0313 |
1 | 20 | 0.9387 | 1.000 | 61/64 | 0.9531 | 31/32 | 0.9688 | 1-1/64 | 1.0156 | 1-1/32 | 1.0313 |
1-1/16 | 18 | 0.9943 | 1.0625 | 1.000 | 1.000 | 1-1/64 | 1.0156 | 1-5/64 | 1.0781 | 1-3/32 | 1.0938 |
1-1/8 | 7 | 0.9497 | 1.1250 | 63/64 | 0.9844 | 1-1/32 | 1.0313 | 1-9/64 | 1.1406 | 1-5/32 | 1.1562 |
1-1/8 | 12 | 1.0228 | 1.1250 | 1-3/64 | 1.0469 | 1-5/64 | 1.0781 | 1-9/64 | 1.1406 | 1-5/32 | 1.1562 |
1-1/8 | 18 | 1.0568 | 1.1250 | 1-1/16 | 1.0625 | 1-5/64 | 1.0781 | 1-9/64 | 1.1406 | 1-5/32 | 1.1562 |
1-3/16 | 18 | 1.1193 | 1.1875 | 1-1/8 | 1.250 | 1-9/64 | 1.1406 | 1-13/64 | 1.2031 | 1-7/32 | 1.2188 |
1-1/4 | 7 | 1.0747 | 1.2500 | 1-7/64 | 1.1094 | 1-5/32 | 1.1562 | 1-17/64 | 1.2656 | 1-9/32 | 1.2812 |
1-1/4 | 12 | 1.1478 | 1.2500 | 1-11/64 | 1.1719 | 1-13/64 | 1.2031 | 1-17/64 | 1.2656 | 1-9/32 | 1.2812 |
1-1/4 | 18 | 1.1818 | 1.2500 | 1-3/16 | 1.1875 | 1-13/64 | 1.2031 | 1-17/64 | 1.2656 | 1-9/32 | 1.2812 |
1-5/16 | 18 | 1.2443 | 1.3125 | 1-1/4 | 1.2500 | 1-17/64 | 1.2656 | 1-21/64 | 1.3281 | 1-11/32 | 1.3438 |
1-3/8 | 6 | 1.1705 | 1.3750 | 1-7/32 | 1.2187 | 1-17/64 | 1.2656 | 1-25/64 | 1.3906 | 1-13/32 | 1.4062 |
1-3/8 | 12 | 1.2728 | 1.3750 | 1-9/64 | 1.2969 | 1-21/64 | 1.3281 | 1-25/64 | 1.3906 | 1-13/32 | 1.4062 |
1-3/8 | 18 | 1.3068 | 1.3750 | 1-5/16 | 1.3125 | 1-21/64 | 1.3281 | 1-25/64 | 1.3906 | 1-13/32 | 1.4062 |
1-7/16 | 18 | 1.3693 | 1.4375 | 1-3/8 | 1.3750 | 1-25/64 | 1.3906 | 1-29/64 | 1.4531 | 1-15/32 | 1.4688 |
1-1/2 | 6 | 1.2955 | 1.5000 | 1-11/32 | 1.3437 | 1-25/64 | 1.3906 | 1-33/64 | 1.5156 | 1-17/32 | 1.5312 |
1-1/2 | 12 | 1.3978 | 1.5000 | 1-27/64 | 1.4219 | 1-7/16 | 1.4375 | 1-33/64 | 1.5156 | 1-17/32 | 1.5312 |
1-1/2 | 18 | 1.4318 | 1.5000 | 1-7/16 | 1.4375 | 1-29/64 | 1.4531 | 1-33/64 | 1.5156 | 1-17/32 | 1.5312 |
1-9/16 | 18 | 1.4943 | 1.5625 | 1-1/2 | 1.5000 | 1-33/64 | 1.5156 | 1-37/64 | 1.5781 | 1-19/32 | 1.5938 |
1-5/8 | 18 | 1.5568 | 1.6250 | 1-9/16 | 1.5625 | 1-37/64 | 1.5781 | 1-41/64 | 1.6406 | 1-21/32 | 1.6562 |
1-11/16 | 18 | 1.6193 | 1.6875 | 1-5/8 | 1.6250 | 1-41/64 | 1.6406 | 1-45/64 | 1.7031 | 1-23/32 | 1.7188 |
1-3/4 | 5 | 1.5046 | 1.7500 | 1-9/16 | 1.5625 | 1-5/8 | 1.6250 | 1-49/64 | 1.7659 | 1-25/32 | 1.7812 |