Tap-Drill Chart - U.S. Customary & Metric Section V - Specifications - Group 18 Page V-48 M11 Tap-Drill Chart - U.S. Customary & Metric NOTE ON SELECTING TAP-DRILL SIZES: The tap drill sizes shown on this card give the theoretical tap drill size for approximately 60% and 75% of full thread depth. Generally, it is recommended that drill sizes be selected in the 60% range as these sizes will provide about 90% of the potential holding power. Drill sizes in the 75% range are recommended for shallow hole tapping (less than 1 1/2 times the hole diameter) in soft metals and mild steel.
Tap Size Drill Size 60% 75% 48 1.95mm 5/64 3-48 47 2.00mm M2.5x.45 2.05mm 46 3-48 3056 45 2.10mm M2.5x.45 M2.6x.45 2.15mm 3-56 4-36 44 2.20mm M2.6x.45 2.25mm 4-36 4-40 43 2.30mm 2.35mm 4-40 4-48 42 3/32 M3x.6 2.40mm 4-48 41 2.45mm 40 M3x.6 M3x.5 2.50mm 39 5-40 38 M3x.5 2.60mm 5-40 5-44 37 2.70mm 5-44 6-32 36 2.75mm 7/64 35 2.80mm 34 6-32 6-40 33 M3.5x6 2.90mm 32 M3.5x6 3.00mm 6-40 31 3.10mm 1/8 3.20mm M4x.75 3.25mm 30 M4x.7 3.30mm M4x.75 3.40mm M4x.7 8-32 29 3.50mm 8-36 28 8-32 9/64 3.60mm 8-36 27 3.70mm 26 M4.5x.75 3.75mm 10-24 25 3.80mm 24 M4.5x.75 3.90mm 23 5/32 10-24 22 M5x1 4.00mm 10-32 21 20 M5x.9 4.10mm M5x1 M5x.8 4.20mm 10-32 19 M5x.9 4.25mm M5x.8 4.30mm 18 11/64 17 Tap Size Drill Size 60% 75% 4.40mm 12-24 16 4.50mm 15 M5.5x.9 4.60mm 12-24 12-28 14 13 4.70mm M5.5x.9 4.75mm 12-28 3/16 12 4.80mm 11 4.90mm 10 9 M6x1 5.00mm 8 5.10mm 1/4-20 7 13/64 6 M6x1 5.20mm 5 M6x.75 5.25mm 5.30mm 1/4-20 4 M6x.75 5.40mm 1/4-28 3 5.50mm 7/32 5.60mm 1/4-28 2 5.70mm 5.75mm 1 5.80mm 5.90mm A 15/64 M7x1 6.00mm B 6.10mm C M7x1 6.20mm D M7x.75 6.25mm 6.30mm E 1/4 M7x.75 6.40mm 6.50mm 5/16-18 F 6.60mm G 6.70mm 17/64 M8x1.25 6.75mm 5/16-18 H 6.80mm 6.90mm 5.16-24 I M8x1.25 M8x1 7.00mm J 7.10mm 5/16-24 K 9/32 M8x1 7.20mm 7.25mm 7.30mm L 7.40mm M Tap Size Drill Size 60% 75% 7.50mm 19/64 7.60mm N 7.70mm M9x1.25 7.75mm 7.80mm 7.90mm 3/8-16 5/16 M9x1.25 M9x1 8.00mm O 8.10mm M9x1 8.20mm P 8.25mm 8.30mm 3/8-16 1/8-27NPT 21/64 8.40mm 3/8-24 Q M10x1.5 8.50mm 8.60mm R 3/8-24 8.70mm 1/8-27NPT 11/32 M10x1.25 8.75mm M10x1.5 8.80mm S 8.90mm M10x1.25 M10x1 9.00mm T 9.10mm 23/64 M10x1 9.20mm 9.30mm 7/16-14 U 9.40mm M11x1.5 9.50mm 3/8 V 9.60mm 9.70mm 9.75mm M11x1.5 9.80mm 7/16-14 W 9.90mm 7/16-20 25/64 10.00mm 7/16-20 X M12x1.75 10.20mm Y 13/32 Z M12x1.75 M12x1.5 10.50mm 1/2-13 27/64 M12x1.5 M12x1.25 10.75mm M12x1.25 11.00mm 1/2-13 7/16 1/4-18NPT 11.25mm 11.50mm 29/64 11.75mm 11.50mm 1/2-20 29/64 9/16-12 15/32 M14x2 12.00m 12.25mm 9/16-12 31/64 M14x2 M14x1.5 12.50mm 9/16-18 1/2 M14x1.5 M14x1.25 12.75mm M14x1.25 13.00mm 9/16-18 33/64 Tap Size Drill Size 60% 75% 13.25mm 5/8-11 17/32 M15x1.5 13.50mm M15x1.5 13.75mm 5/8-11 35/64 M16x2 14.00mm 14.25mm 5/8-18 9/16 M16x2 M16x1.5 14.50mm 5/8-18 37/64 14.75mm M16x1.5 15.00mm 19.32 15.25mm 39/64 M17x1.5 15.50mm M17x1.5 M18x2.5 15.75mm 5/8 M18x2.5 M18x2 16.00mm M18x2 16.25mm 3/4-10 41/64 M18x1.5 16.50mm 3/4-10 M19x2.5 21/32 M18x1.5 16.75mm M19x2.5 17.00mm 43/64 17.25mm 3/4-16 3/4-16 11/16 M20x2.5 17.50mm 17.75mm 45/64 M20x2.5 M20x2 18.00mm M20x2 18.25mm 23/32 M20x1.5 18.50mm 47/64 M20x1.5 18.75mm 19.00mm 3/4 19.25mm 7/8-9 49/64 M22x2.5 19.50mm 7/8-9 25/32 19.75mm M22x2.5 M22x2 20.00mm 7/8-14 51/64 M22x2 20.25mm M22x1.5 20.50mm 7/8-14 13/16 20.75mm M22x1.5 M24x3 21.00mm 53/64 21/25mm 27/32 M24x3 21.50mm 21.75mm 55/64 M24x2 22.00mm 1 -8 7/8 M24x2 22.25mm M24x1.5 22.50mm 1 -8 57/64 M24x1.5 22.75mm M25x2 23.00mm 1 -12 29/32 M25x2 23.25mm 1 x12 1 -14 59/64 M25x1.5 23.50mm M20x1.5 23.75mm 1 -14 15/16