Pre Tap Drill Size

Metric Form Tap

Tap
Drill Size
Decimal Equivalent
M18 x 1.50
17.25MM
0.6791
M18 x 2.50
39/64
0.6094
M16 x 1.50
15.25MM
0.6004
M16 x 2.00
19/32
0.5938
M14 x 2.00
33/64
0.5156
M12 x 1.25
11.50MM
0.4528
M12 x 1.75
11.20MM
0.4409
M10 x 1.25
9.40 MM
0.3701
M10 x 1.50
U
0.3680
M8 x 1.00
19/64
0.2969
M8 x 1.25
7.40MM
0.2913
M7 x 1.00
F
0.2570
M6 x 1.00
7/32
0.2188
M5 x 0.80
14
0.1820
M4.5 x 0.75
4.10MM
0.1612
M4 x 0.70
3.70MM
0.1476
M3.50 x 0.60
3.20MM
0.1260
M3 x 0.50
7/64
0.1094
M2.5 x 0.45
2.30MM
0.0906
M2.2 x 0.45
2.00MM
0.0787
M2 x 0.40
1.80MM
0.0709
M1.8 x 0.35
1.65MM
0.0650
M1.6 x 0.35
1.45MM
0.0571
Inch Cutting Tap