Cutting Parameters
Practical starting values for cutting speed, feed and spindle speed for turning, milling, drilling and tapping. Adjust for machine rigidity, tooling and batch before production.
Cutting Speed & Spindle Speed
Cutting speed is the relative surface speed between tool and workpiece. Convert to spindle speed with:
- v — cutting speed (m/min)
- D — diameter (mm)
- n — spindle speed (rev/min)
Tool material selection
- HSS — general-purpose drills, taps, reamers; low cost, tough.
- Carbide (WC-Co) — high speeds, turning and milling of steel and cast iron.
- Coated (TiN, TiAlN) — longer life, dry or hardened-steel machining.
- Reduce speed 20 – 30% for interrupted cuts, thin sections or weak setups.
- Increase feed slightly for roughing, reduce for finishing and fine surface finish.
- Always check tool catalog data and machine limits before production.
Turning — starting values
| Work material | v (m/min) | f (mm/rev) |
|---|---|---|
| Free-cutting steel (12L14) | 180 – 250 | 0.15 – 0.40 |
| Carbon steel (C45) | 150 – 220 | 0.20 – 0.50 |
| Alloy steel (40Cr) | 120 – 180 | 0.15 – 0.40 |
| Stainless steel | 90 – 150 | 0.10 – 0.30 |
| Cast iron (HT200) | 60 – 100 | 0.20 – 0.60 |
| Aluminium | 300 – 600 | 0.10 – 0.50 |
| Operation | v (m/min) | fz (mm/tooth) |
|---|---|---|
| Steel roughing | 120 – 180 | 0.15 – 0.30 |
| Steel finishing | 150 – 220 | 0.05 – 0.15 |
| Cast iron | 80 – 140 | 0.15 – 0.30 |
| Aluminium | 300 – 600 | 0.10 – 0.25 |
| Stainless steel | 80 – 130 | 0.05 – 0.15 |
fz — feed per tooth.
Drilling (HSS twist drill) — starting values
| Work material | v (m/min) | f (mm/rev) |
|---|---|---|
| Steel | 18 – 25 | 0.10 – 0.25 |
| Cast iron | 15 – 25 | 0.15 – 0.30 |
| Aluminium | 40 – 70 | 0.15 – 0.35 |
| Stainless steel | 8 – 12 | 0.05 – 0.15 |
Tapping (HSS tap) — starting values
| Work material | v (m/min) |
|---|---|
| Steel | 8 – 15 |
| Cast iron | 8 – 12 |
| Aluminium | 12 – 20 |
Tool geometry & chip formation
Single-point tool angles
Rake angle γ faces the chip; clearance angle α clears the fresh surface below the cutting edge. Together they set the wedge angle β = 90° − (γ + α).
Chip formation
The tool compresses the material ahead of the edge; the metal shears along a shear zone and flows up the rake face as a chip. A built-up edge (BUE) can form at low speed.
Indexable insert geometry
Inserts are shaped by their approach angle κ, nose radius rε and chipbreaker. Larger nose radius strengthens the edge; smaller gives finer finish.