Introduction
Professional copper-alloy milling calculator. Covers brass, bronze, and pure copper with BUE risk analysis and routing for turning or drilling workflows.
How It Works
Enter the planning inputs for this calculator, review the computed output, and compare the result against your machine limits, tooling, material, and shop-floor validation workflow.
Key Formulas
Use the formulas, assumptions, and process notes on this page to validate the result before applying it to a quote, investment case, or live machining setup.
How to Use
Follow the step-by-step guidance, worked examples, and caution notes on the page before locking in the final numbers for production or procurement.
Related Calculators
Use the related calculator links on this page when the current workflow needs a more specific model for speed, feed, cost, capacity, maintenance, or machine selection.
Copper, Brass & Bronze Speeds & Feeds Calculator 2026
Set a first-pass RPM, chip load, and feed for copper-alloy milling across pure copper, tellurium copper, brass, bronze, and BeCu. Built for milling workflows first, with drilling and turning routed to the dedicated calculators.
Calculate Copper-Alloy Milling Parameters
Copper Alloy Machining Guide
Copper-alloy search intent is split across pure copper, brass, and bronze families, but the reliable overlap on this page is still milling. This calculator is strongest when alloy family, cutter size, chip load, and built-up-edge risk drive the setup. Turning, drilling, boring, and reaming should move to their dedicated calculators before release because feed-per-rev logic and breakthrough behavior are different.
What This Page Covers Best
Copper-alloy milling start points for pure copper, free-cutting brass, naval brass, phosphor bronze, bearing bronze, and BeCu where BUE risk and chip control matter more than hardness alone.
Where It Needs Backup
Drilling and turning need feed-per-rev logic, and boring or reaming need tool-specific geometry rules. BeCu safety planning also needs process controls beyond a simple speed-and-feed result.
Best Next Links
Use the main feeds and speeds calculator for the broader cutter workflow, then branch to the brass chart, bronze chart, drilling calculator, or turning calculator when the job becomes process-specific.
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. The turning column is reference-only here; validate any real turning setup in the dedicated turning calculator.
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.
Copper-Alloy Workflow Tools
General Feeds & Speeds
Return to the main CNC feeds and speeds calculator for RPM, feed rate, chip load, SFM, MRR, and power context.
Brass Chart
Quick-reference ranges for C360, C260, C464, and high-speed brass workflows.
Bronze Chart
Quick-reference ranges for bearing, phosphor, and aluminum bronze grades.
Drilling Calculator
Use feed-per-rev and breakthrough guidance instead of guessing from milling data.
Turning Calculator
Switch here for OD/ID copper-alloy work where turning feed and DOC drive the setup.