Roughing removes stock; finishing prioritizes size and surface quality. Choose cutting data for the insert, work material and setup rigidity—not from diameter alone.
| Quantity | Relationship | Units / scope |
|---|---|---|
| Radial cutting depth | ap = (D − d) / 2 | Outside turning: starting diameter D and finished diameter d, in mm. |
| Spindle speed | n = 1000 · vc / (π · Dm) | vc: m/min; machining diameter Dm: mm; n: rev/min. |
| Axial feed rate | vf = f · n | f: mm/rev; vf: mm/min. |
| One-pass cutting time | tc = L / (f · n) | L: feed travel in mm; tc: min, at constant n and f. |
Radial depth is 2 mm, not 4 mm. Assume 600 rev/min, 0.20 mm/rev and 60 mm feed travel: 120 mm/min and 30 s. At Ø50 mm, cutting speed is approximately 94.2 m/min. These hypothetical inputs are not a cutting recommendation; handling and return time are excluded.
For an ideal rounded tool nose, theoretical profile height is approximately Rth = f² / (8rε), with all lengths in mm. At f = 0.20 mm/rev and rε = 0.8 mm, this gives 6.25 µm. It is not Ra or a guarantee of measured finish: vibration, wear and built-up edge matter.