ISO METRIC THREADS COARSE 
TAPPING DRILL SIZES
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SIZE  OUT   CORE PITCH TAP   DEP
      DIA.  DIA.       DRILL  TH
        mm    mm    mm    mm   %
                                
M2     2.0  1.51  0.40  1.75  51
M2     2.0  1.51  0.40  1.70  61
M2     2.0  1.51  0.40  1.65  71
                                
M2.5   2.5  1.95  0.45  2.20  54
M2.5   2.5  1.95  0.45  2.15  63
M2.5   2.5  1.95  0.45  2.10  72
                                
M3     3.0  2.39  0.50  2.65  57
M3     3.0  2.39  0.50  2.60  65
M3     3.0  2.39  0.50  2.55  73
                                
M4     4.0  3.14  0.70  3.50  58
M4     4.0  3.14  0.70  3.45  64
M4     4.0  3.14  0.70  3.40  70
                                
M5     5.0  4.02  0.80  4.40  61
M5     5.0  4.02  0.80  4.30  71
M5     5.0  4.02  0.80  4.20  82
                                
M6     6.0  4.77  1.00  5.30  57
M6     6.0  4.77  1.00  5.20  65
M6     6.0  4.77  1.00  5.10  73
                                
M8     8.0  6.47  1.25  7.10  59
M8     8.0  6.47  1.25  7.00  65
M8     8.0  6.47  1.25  6.90  72
                                
M10   10.0  8.16  1.50  8.90  60
M10   10.0  8.16  1.50  8.80  65
M10   10.0  8.16  1.50  8.70  71
                                
M12   12.0  9.85  1.75 10.70  61
M12   12.0  9.85  1.75 10.60  65
M12   12.0  9.85  1.75 10.50  70
                                
M16   16.0 13.55  2.00 14.50  61
M16   16.0 13.55  2.00 14.40  65
M16   16.0 13.55  2.00 14.30  69