When tapping M4, M5, M6, M8 and M10, how big bits of drill (ordinary steel) are used?
Extrusion tap:Screw - pitch: D=d1-0.49P P = 2. In the case of M10x1.5, hole size D=10-0.49 * 1.5=9.27. (recommendation 9.3)Screw - pitch: D=d1-0.42P P = 0.8. In the case of M3x0.5, hole size D=3-0.42 * 0.5=2.79. (recommendation 2.8)Therefore, cutting tap hole were recommended as follows: 3.3, 4.2, 5, 6.8, 8.5
Stainless steel, titanium alloy, steel and other materials hard to be machined: D=d1-0.95P. Still in the case of M10x1.5, hole size D=10-0.95 * 1.5=8.575. (recommendation 8.6)
Medium and low strength alloy steel, cast iron and other easily processed materials: D=d1-P, in which D1 is thread nominal diameter (big diameter), and P is thread pitch. In the case of M10x1.5, hole size D=10-1.5=8.5.
