Copper & Brass Speeds & Feeds Calculator 2026
Optimized parameters for copper, brass, and bronze alloys. Includes BUE risk analysis and EP coolant recommendations.
Calculate Copper Parameters
Copper Alloy Machining Guide
Copper alloys range from extremely difficult to machine (pure copper) to the easiest material in manufacturing (free-cutting brass). Understanding the differences is essential for optimal machining.
Copper Alloy Categories
🟠 Pure Copper
Machinability: 20% (Very Difficult)
Extremely gummy and ductile. Forms long, stringy chips. Built-up edge is a constant challenge. Requires EP cutting fluid and high speeds.
- • C110 ETP: Electrical applications
- • C101 OFHC: Vacuum, semiconductors
- • C145 Tellurium: Free machining copper (85%)
🟡 Brass
Machinability: 30-100%
Copper + Zinc alloys. Free-cutting brass (C360) is the machinability benchmark. Non-leaded brasses are more difficult but still much easier than pure copper.
- • C360: Free Cutting (100%) - Gold Standard
- • C260: Cartridge Brass (30%)
- • C464: Naval Brass (30%)
🟤 Bronze
Machinability: 20-80%
Copper + Tin alloys. Harder than brass but more abrasive. Phosphor bronze is particularly challenging. Free-cutting grades add lead for improved machining.
- • C510: Phosphor Bronze (20%)
- • C544: Free Cut Phosphor Bronze (80%)
- • C932: Bearing Bronze (70%)
🔴 Beryllium Copper
⚠️ TOXIC DUST - Use Wet Cutting Only
High strength copper alloy for springs and molds. Beryllium dust is highly toxic and can cause fatal lung disease. Never grind or dry machine.
- • ALWAYS use flood coolant
- • Proper dust extraction required
- • Follow OSHA regulations
Cutting Speed Reference
| Alloy | Machin. | Milling (m/min) | Turning (m/min) | Notes |
|---|---|---|---|---|
| C360 Free Cutting Brass | 100% | 250-650 | 350-900 | Benchmark! |
| C145 Tellurium Cu | 85% | 200-500 | 280-650 | Best for pure Cu |
| C544 Free Cut Bronze | 80% | 180-460 | 240-600 | Easy bronze |
| C260 Cartridge Brass | 30% | 120-280 | 150-350 | Chip control needed |
| C110 Pure Copper | 20% | 150-350 | 200-500 | Gummy, BUE |
| C510 Phosphor Bronze | 20% | 80-200 | 100-260 | Hard, abrasive |
* Speeds for uncoated carbide. PCD can run 2-3× faster on pure copper.
Built-Up Edge Prevention
Built-Up Edge (BUE) is the main challenge when machining copper. Material welds to the cutting edge, affecting surface finish and tool life.
✓ Prevention Methods
- • Use high cutting speeds
- • EP (Extreme Pressure) cutting fluid
- • Sharp, polished cutting edges
- • Positive rake geometry
- • Use adequate chip load (no rubbing)
✗ Things That Cause BUE
- • Low cutting speeds
- • Dry machining
- • Dull tools
- • Too light feed (rubbing)
- • Coated tools (on pure copper)
Frequently Asked Questions
Pure copper (C110, C101) has only 20% machinability compared to free-cutting brass. Its high ductility causes gummy chips, built-up edge (BUE), and poor chip breaking. The solution is higher cutting speeds, sharp tools, EP cutting fluid, and free-machining grades like tellurium copper (C145) when possible.