Tap size Major
Dia (mm)
Threads
per
Tap Drill
(mm)
Tap Drill
(inch)
Clearance
(mm)
Clearance
(inch
M1.6x0.35 1.6 0.35 1.25 #55 1.8 #49
M2x0.4 2.0 0.40 1.60 #52 2.4 #41
M2.5x0.45 2.5 0.45 2.05 #46 2.9 #32
M3x.05 3.0 0.50 2.50 #39 3.4 #29
M3.5x0.6 3.5 0.60 2.90 #32 3.9 #23
M4x0.7 4.0 0.70 3.30 #30 4.5 #16
M5x0.8 5.0 0.80 4.20 #19 5.5 7/32
M6x1 6.0 1.00 5.0 #8 6.6 G
M8x1.25 8.0 1.25 6.8 H 9.0 T
M8x1 8.0 1.00 7.0 J 9.0 T
M10x1.5 10.0 1.50 8.5 R 12.0 31/64
M10x1.25 10.0 1.25 8.8 11/32 12.0 31/64
M12x1.75 12.0 1.75 10.2 13/32 14.0 35/64
M12x1.25 12.0 1.25 10.8 27/64 14.0 35/64
M14x2 14.0 2.00 12.0 15/32 16.0 5/8
M14x1.5 14.0 1.5 12.5 1/2 16.0 5/8
M16x2 16.0 2.00 14.0 35/64 18.0 45/64
M16x1.5 16.0 1.50 14.5 37/64 18.0 45/64
M18x2.5 18.0 2.50 15.5 39/64 20.0 51/64
M18x1.5 18.0 1.50 16.5 21/32 20.0 51/64
M20x2.5 20.0 2.50 17.5 11/16 22.0 7/8
M20x1.5 20.0 1.50 18.5 47/64 22.0 7/8
M22x2.5 22.0 2.50 19.5 49/64 25.0 1
M22x1.5 22.0 1.50 20.5 13/16 25.0 1
M24x3 24.0 3.00 21.0 53/64 27.0 1-5/64
M24x2 24.0 2.00 22.0 7/8 27.0 1-5/64
M27x3 27.0 3.00 24.0 15/16 30.0 1-3/16
M27x2 27.0 2.0 25.0 1 30.0 1-3/16