Pure copper (C110) is soft, ductile, and gummy — the opposite of brass to cut. It smears and forms built-up edge easily, so very sharp, high-rake, polished tools and plenty of lubricant are the key.
Key properties
| Property | Typical value |
|---|---|
| Density | 0.323 lb/in³ (8.94 g/cm³) |
| Hardness | ~40 HRB |
| Tensile strength | ~32,000 psi (220 MPa) |
| Machinability | Fair (gummy) |
| Composition | ~99.9% Cu (C110) |
Cutting speeds
| Operation | HSS (SFM) | Carbide (SFM) |
|---|---|---|
| Milling | 100 – 200 | 300 – 600 |
| Turning | 150 – 250 | 400 – 700 |
| Drilling | 100 – 200 | 300 – 500 |
Convert to RPM: RPM = (SFM × 3.82) / cutter diameter. Use the Feeds & Speeds calculators.
Tooling and tips
- Very sharp, polished, high-rake tools to slice rather than smear.
- Use generous lubricant to fight built-up edge.
- Keep a steady feed; copper loves to gum up and grab at light cuts.
See Feeds and Speeds Chart and the full Feeds and Speeds Chart.