Metric Tap Drills


Tap size Major Diameter Millimeters Tap Drill
mm inch Per Thread Size mm Dia.
M1.6 x 0.35 1.6 .063 .35 #55 1.25 .052
M2 x 0.4 2 .079 .4 #52 1.6 .064
M2.5 x 0.45 2.5 .098 .45 #46 2.05 .081
M3 x .05 3 .118 .5 #39 2.5 .100
M3.5 x 0.6 3.5 .138 .6 #32 2.9 .116
M4 x 0.7 4 .158 .7 #30 3.3 .129
M5 x 0.8 5 .197 .8 #19 4.2 .177
M6 x 1 6 .236 1 #8 5 .199
M8 x 1.25 8 .315 1.25 H 6.8 .266
M8 x 1 8 .315 1 J 7 .277
M10 x 1.5 10 .394 1.5 R 8.5 .339
M10 x 1.25 10 .394 1.25 11/32 8.8 .344
M12 x 1.75 12 .472 1.75 13/32 10.2 .406
M12 x 1.25 12 .472 1.25 27/64 10.8 .422
M14 x 2 14 .551 2 15/32 12 .469
M14 x 1.5 14 .551 1.5 1/2 12.5 .500
M16 x 2 16 .630 2 35/64 14 .547
M16 x 1.5 16 .630 1.5 37/64 14.5 .578
M18 x 2.5 18 .709 2.5 39/64 15.5 .609
M18 x 1.5 18 .709 1.5 21/32 16.5 .656
M20 x 2.5 20 .787 2.5 11/16 17.5 .688
M20 x 1.5 20 .787 1.5 47/64 18.5 .734
M22 x 2.5 22 .866 2.5 49/64 19.5 .766
M22 x 1.5 22 .866 1.5 13/16 20.5 .813
M24 x 3 24 .945 3 53/64 21 .828
M24 x 2 24 .945 2 7/8 22 .875
M27 x 3 27 1.063 3 15/16 24 .938
M27 x 2 27 1.063 2 1" 25 1.000