Tap Chart - Metric Threads
Basic major   Basic major dia   mm per   Drill size   Drill size
  Tap size
                dia (mm)         (inch)        thread     (mm)        (inch)
 M1.6 x 0.35     1,6mm            .0630          .35    1,25mm          #55
  M2 x 0.4        2mm             .0787           .4     1,6mm          #52
 M2.5 x 0.45     2,5mm            .0984          .45    2,05mm          #46
  M3 x .05        3mm             .1181           .5     2,5mm          #39
 M3.5 x 0.6      3,5mm            .1378           .6     2,9mm          #32
  M4 x 0.7        4mm             .1575           .7     3,3mm          #30
  M5 x 0.8        5mm             .1969           .8     4,2mm          #19
  M6 x 1          6mm             .2362            1      5mm            #8
 M8 x 1.25        8mm             .3150         1.25     6,8mm           H
  M8 x 1          8mm             .3150            1      7mm             J
 M10 x 1.5       10mm             .3937          1.5     8,5mm           R
 M10 x 1.25      10mm             .3937         1.25     8,8mm        11/32
 M12 x 1.75      12mm             .4724         1.75    10,2mm        13/32
 M12 x 1.25      12mm             .4724         1.25    10,8mm        27/64
  M14 x 2        14mm             .5512            2     12mm         15/32
 M14 x 1.5       14mm             .5512          1.5    12,5mm          1/2
  M16 x 2        16mm             .6299            2     14mm         35/64
 M16 x 1.5       16mm             .6299          1.5    14,5mm        37/64
 M18 x 2.5       18mm             .7087          2.5    15,5mm        39/64
 M18 x 1.5       18mm             .7087          1.5    16,5mm        21/32
 M20 x 2.5       20mm             .7874          2.5    17,5mm        11/16
 M20 x 1.5       20mm             .7874          1.5    18,5mm        47/64
 M22 x 2.5       22mm             .8661          2.5    19,5mm        49/64
 M22 x 1.5       22mm             .8661          1.5    20,5mm        13/16
  M24 x 3        24mm             .9449            3     21mm         53/64
  M24 x 2        24mm             .9449            2     22mm           7/8
  M27 x 3        27mm            1.0630            3     24mm         15/16
  M27 x 2        27mm            1.0630            2     25mm             1