| Material |
Hardness(HRC) |
Speed-FPM(m) |
| Low Carbon |
<=10 |
25-50 |
| Mid-carbon Steel |
<=15 |
20-40 |
| High-Carbon Steel |
<=25 |
20-50 |
| High Strenghth Steel |
25-32 |
20-30 |
| Stainless Steel (304, 316) |
<=25 |
20-30 |
| Cast Iron |
<=15 |
20-40 |
| Copper |
- |
25-60 |
¡¡¡¡The above table and formule is fit for cylinder tap,
if it's taper tap, the speed will be decreased 1/2-1/4. |
