Metric Tap & Clearance Drill Sizes Tap Drill 75% Thread for Aluminum, Brass, & Plastics Screw Size (mm) Thread Pitch (mm) Drill Size (mm) M1.5 M1.6 M 1.8 0.35 0.35 0.35 0.45 0.40 0.45 0.45 0.60 0.50 0.60 0.75 0.70 0.75 1.00 0.90 0.80 0.90 1.00 0.75 1.00 0.75 1.25 1.00 1.25 1.00 1.50 1.25 1.00 1.50 1.75 1.50 1.25 2.00 1.50 1.25 1.50 2.00 1.50 1.50 2.50 2.00 1.50 2.50 2.50 2.00 1.50 1.15 1.25 1.45 1.55 1.60 1.75 2.05 2.40 2.50 2.90 3.25 3.30 3.75 4.00 4.10 4.20 4.60 5.00 5.25 6.00 6.25 6.80 7.00 7.80 8.00 8.50 8.80 9.00 9.50 10.30 10.50 10.80 12.10 12.50 12.80 13.50 14.00 14.50 15.50 15.50 16.00 16.50 16.50 17.50 18.00 18.50 M2 M 2.2 M 2.5 M3 M 3.5 M4 M 4.5 M5 M 5.5 M6 M7 M8 M9 M 10 M 11 M 12 M 14 M 15 M 16 M 17 M 18 M 19 M 20 Closest American Drill 56 55 53 1/16 52 50 46 41 39 32 30 30 25 21 20 19 14 8 4 B D H J N O R 11/32 T 3/8 13/32 Z 27/64 15/32 1/2 1/2 17/32 35/64 37/64 39/64 39/64 5/8 21/32 21/32 11/16 45/64 47/64 Clearance Drill 50% Thread for Steel, Stainless, & Iron Drill Size (mm) 1.25 1.35 1.55 1.70 1.75 1.90 2.20 2.60 2.70 3.10 3.50 3.50 4.00 4.40 4.40 4.50 4.90 5.40 5.50 6.40 6.50 7.20 7.40 8.20 8.40 9.00 9.20 9.40 10.00 10.90 11.00 11.20 12.70 13.00 13.20 14.00 14.75 15.00 16.00 16.50 16.75 17.00 17.50 18.50 18.50 19.00 Closest American Drill 55 54 1/16 51 50 48 44 37 36 31 28 28 22 11/64 17 16 10 4 7/32 E F J L P 21/64 T 23/64 U X 27/64 7/16 7/16 1/2 33/64 33/64 35/64 37/64 19/32 5/8 41/64 21/32 43/64 11/16 23/32 47/64 3/4 Close Fit Standard Fit 1.60 1.70 1.90 Closest American Drill 1/16 51 49 1.65 1.75 2.00 Closest American Drill 52 50 5/64 2.10 45 2.20 44 2.30 2.65 3/32 37 2.40 2.75 41 7/64 3.15 1/8 3.30 30 3.70 27 3.85 24 4.20 19 4.40 17 4.75 13 5.00 9 5.25 5 5.50 7/32 5.80 1 6.10 B 6.30 E 6.60 G 7.40 L 7.70 N 8.40 Q 8.80 S 9.50 3/8 9.90 25/64 10.50 Z 11.00 7/16 11.60 29/64 12.10 15/32 12.60 1/2 13.20 33/64 14.75 37/64 15.50 39/64 15.75 5/8 16.50 21/32 16.75 21/32 17.50 11/16 18.00 45/64 18.50 47/64 19.00 3/4 20.00 25/32 20.00 25/32 21.00 53/64 21.00 53/64 22.00 55/64 Drill Size (mm) Drill Size (mm) the premier source of parts and accessories for mini lathes and mini mills LittleMachineShop.com • (800) 981-9663 the premier source of parts and accessories for mini lathes and mini mills LittleMachineShop.com • (800) 981-9663 Tap & Clearance Drill Sizes Screw Size Major Diameter Threads Per Inch Minor Diameter 0 .0600 1 .0730 2 .0860 3 .0990 4 .1120 5 .125 6 .138 8 .1640 10 .1900 12 .2160 1/4 .2500 5/16 .3125 3/8 .3750 7/16 .4375 1/2 .5000 9/16 .5625 5/8 .6250 11/16 .6875 3/4 .7500 13/16 .8125 7/8 .8750 15/16 .9375 1 1.000 80 64 72 56 64 48 56 40 48 40 44 32 40 32 36 24 32 24 28 32 20 28 32 18 24 32 16 24 32 14 20 28 13 20 28 12 18 24 11 18 24 24 10 16 20 20 9 14 20 20 8 12 20 .0447 .0538 .0560 .0641 .0668 .0734 .0771 .0813 .0864 .0943 .0971 .0997 .1073 .1257 .1299 .1389 .1517 .1649 .1722 .1777 .1887 .2062 .2117 .2443 .2614 .2742 .2983 .3239 .3367 .3499 .3762 .3937 .4056 .4387 .4562 .4603 .4943 .5114 .5135 .5568 .5739 .6364 .6273 .6733 .6887 .7512 .7387 .7874 .8137 .8762 .8466 .8978 .9387 Tap Drill 75% Thread for Aluminum, Brass, & Plastics Drill Size Dec. Eq. 3/64 .0469 53 .0595 53 .0595 50 .0700 50 .0700 47 .0785 45 .0820 43 .0890 42 .0935 38 .1015 37 .1040 36 .1065 33 .1130 29 .1360 29 .1360 25 .1495 21 .1590 16 .1770 14 .1820 13 .1850 7 .2010 3 .2130 7/32 .2188 F .2570 I .2720 9/32 .2812 5/16 .3125 Q .3320 11/32 .3438 U .3680 25/64 .3906 Y .4040 27/64 .4219 29/64 .4531 15/32 .4688 31/64 .4844 33/64 .5156 33/64 .5156 17/32 .5312 37/64 .5781 37/64 .5781 41/64 .6406 21/32 .6562 11/16 .6875 45/64 .7031 49/64 .7656 49/64 .7656 13/16 .8125 53/64 .8281 57/64 .8906 7/8 .8750 15/16 .9375 61/64 .9531 50% Thread for Steel, Stainless, & Iron Drill Size Dec. Eq. 55 .0520 1/16 .0625 52 .0635 49 .0730 48 .0760 44 .0860 43 .0890 41 .0960 40 .0980 7/64 .1094 35 .1100 32 .1160 31 .1200 27 .1440 26 .1470 20 .1610 18 .1695 12 .1890 10 .1935 9 .1960 7/32 .2188 1 .2280 1 .2280 J .2770 9/32 .2812 L .2900 Q .3320 S .3480 T .3580 25/64 .3906 13/32 .4062 Z .4130 29/64 .4531 15/32 .4688 15/32 .4688 33/64 .5156 17/32 .5312 17/32 .5312 9/16 .5625 19/32 .5938 19/32 .5938 21/32 .6562 11/16 .6875 45/64 .7031 23/32 .7188 25/32 .7812 51/64 .7969 53/64 .8281 27/32 .8438 29/32 .9062 59/64 .9219 61/64 .9531 31/32 .9688 Clearance Drill Close Fit Free Fit Drill Size 52 Dec. Eq. .0635 Drill Size 50 Dec. Eq. .0700 48 .0760 46 .0810 43 .0890 41 .0960 37 .1040 35 .1100 32 .1160 30 .1285 30 .1285 29 .1360 27 .1440 25 .1495 18 .1695 16 .1770 9 .1960 7 .2010 2 .2210 1 .2280 F .2570 H .2660 P .3230 Q .3320 W .3860 X .3970 29/64 .4531 15/32 .4687 33/64 .5156 17/32 .5312 37/64 .5781 19/32 .5938 41/64 .6406 21/32 .6562 45/64 .7031 23/32 .7188 49/64 .7656 25/32 .7812 53/64 .8281 27/32 .8438 57/64 .8906 29/32 .9062 61/64 .9531 31/32 .9688 1-1/64 1.0156 1-1/32 1.0313