Tapping Drill sizes and Clearance Drill Sizes for Metric Threads
Normal Tapping Drill Clearance Drill Size (mm)
Size Size (mm)
Coarse Fire Close Medium Force
M 1.6 1.25 1.7 1.8 2.0
M 2 1.60 2.2 2.4 2.6
M 2.5 2.05 2.7 2.9 3.1
M 3 2.50 3.2 3.4 3.6
M 4 3.30 4.3 4.5 4.8
M 5 4.20 5.3 5.5 5.8
M 6 5.0 5.20 6.4 6.6 7.0
M 8 6.80 7.00 8.4 9.0 10.0
M 10 8.50 8.80 10.5 11.0 12.0
M 12 10.20 10.80 13.0 14.0 15.0
M 14 12.00 12.50 15.0 16.0 17.0
M 16 14.00 14.50 17.0 18.0 19.0
M 18 15.50 16.50 19.0 20.0 21.0
M 20 17.50 18.50 21.0 22.0 24.0
M 22 19.50 20.50 23.0 24.0 26.0
M 24 21.00 22.00 25.0 26.0 28.0
M 27 24.00 25.00 28.0 30.0 32.0
M 30 26.50 31.00 34.0 33.0 38.0
M 33 29.50 33.00 37.0 33.0 42.0
M 36 32.00 31.00 34.0 36.0 38.0
M 39 35.00 36.00 40.0 42.0 45.0
M 42 37.50 39.00 43.0 45.0 48.0