CNC Machining Guide: Copper vs Brass

A Comprehensive Technical Comparison Focused on CNC Machining Processes

• Machining Difficulty: ★★★★☆ (Difficult)

• Surface Quality: ★★★☆☆ (Medium)

• Machining Efficiency: ★★☆☆☆ (Low)

• Tool Life: ★★☆☆☆ (Short)

• Cost Efficiency: ★★☆☆☆ (Low)

• Machining Difficulty: ★★☆☆☆ (Easy)

• Surface Quality: ★★★★☆ (Good)

• Machining Efficiency: ★★★★☆ (High)

• Tool Life: ★★★★☆ (Long)

• Cost Efficiency: ★★★★★ (Excellent)

• Material Property: Extremely high ductility, good toughness

• Chip Formation: Continuous ribbon chips, difficult to break

• Tool Adhesion: Severe,

• Surface Roughness: Ra 1.6-3.2μm

• Machining Challenges:

• • Chip entanglement on tools

• • Surface scratching issues

• • Dimensional control difficulties

• Material Property: Moderate brittleness, easy to cut

• Chip Formation: Fragmented or spiral chips, easy to break

• Tool Adhesion: Minimal, less built-up edge formation

• Surface Roughness: Ra 0.8-1.6μm

• Machining Advantages:

• • Easy chip evacuation

• • Good surface quality

• • High dimensional accuracy

• Preferred: Ultra-fine grain carbide

• Alternative: High-speed steel (HSS-Co)

• Recommended Coating: TiAlN or diamond coating

• Rake Angle: 15°-20° (larger angle reduces cutting force)

• Clearance Angle: 8°-12°

• Edge Angle: 0°-5°

• Tool Nose Radius: 0.4-1.2mm

• Milling Speed: 1000-3000 rpm

• Feed Rate: 100-300 mm/min

• Cutting Depth: ≤5mm (roughing), ≤1mm (finishing)

• Cutting Width: 50-70% of tool diameter

• Preferred: High-speed steel (HSS)

• Alternative: Regular carbide

• Recommended Coating: TiN coating or uncoated

• Rake Angle: 10°-15°

• Clearance Angle: 6°-10°

• Edge Angle: 0°-3°

• Tool Nose Radius: 0.2-0.8mm

• Milling Speed: 2000-5000 rpm

• Feed Rate: 200-500 mm/min

• Cutting Depth: 10-20mm (roughing), 1-3mm (finishing)

• Cutting Width: 60-80% of tool diameter

• Type: Extreme pressure emulsion or synthetic cutting fluid

• Concentration: 8-12%

• Flow Rate: Sufficient for continuous cooling

• Pressure: Medium pressure to avoid splashing

• Use high-pressure cooling system

• Direct cooling to cutting zone

• Maintain clean cutting fluid

• Regular fluid replacement

• Type: Emulsion or micro-emulsion

• Concentration: 5-8%

• Flow Rate: Moderate

• Pressure: Low pressure

• Regular cooling system sufficient

• Main function is chip evacuation and lubrication

• Can reduce cooling intensity appropriately

• Clamping Force: Requires high clamping force

• Fixture Material: Use soft jaws or copper fixtures

• Positioning Accuracy: High precision positioning

• Use multiple clamping points

• Avoid workpiece deformation

• Use End face positioning

• Consider vacuum fixtures if possible

• Clamping Force: Medium clamping force sufficient

• Fixture Material: Standard steel fixtures

• Positioning Accuracy: Regular precision

• Standard clamping methods

• Easy to achieve reliable holding

• Can use regular fixtures

1. Roughing: Low feed rate, small depth of cut

2. Semi-finishing: Medium parameters, remove most material

3. Finishing: High speed, low feed rate, small depth of cut

• Multiple passes to gradually remove material

• Timely chip removal

• Monitor tool wear carefully

• Control machining temperature

1. Roughing: High feed rate, large depth of cut

2. Finishing: One pass or minimal passes

• Can use larger cutting parameters

• High machining efficiency

• Long tool life

• Easy to Ensure precision

• Symptom: Chips adhere to tool and workpiece

• Cause: High material ductility, high cutting temperature

• Solutions:

• • Use sharp tools

• • Increase cutting speed

• • Improve cooling and lubrication

• • Reduce feed rate

• Symptom: High surface roughness, scratches

• Cause: Chip scratching, tool wear

• Solutions:

• • Use new tools

• • Optimize cutting parameters

• • Improve cooling conditions

• • Clean chips promptly

• Symptom: Unstable dimensions, out of tolerance

• Cause: Material thermal expansion, tool wear

• Solutions:

• • Control machining temperature

• • Measure dimensions frequently

• • Replace tools timely

• • Consider thermal expansion compensation

• Symptom: Severe local tool wear

• Cause: Hard particles in material

• Solutions:

• • Select appropriate tool material

• • Optimize cutting parameters

• • Improve cooling conditions

• Symptom: Wavy surface after machining

• Cause: Improper cutting parameters, insufficient rigidity

• Solutions:

• • Adjust cutting parameters

• • Increase system rigidity

• • Use vibration damping measures

• Dimensional Accuracy: Check every 10-15 minutes

• Surface Quality: Continuous monitoring, detect problems timely

• Tool Condition: Frequent inspection of tool wear

• Chip Condition: Observe chip formation changes

• Use high-precision measuring tools

• Establish quality inspection system

• Record machining parameters and quality data

• Adjust machining process timely

• Dimensional Accuracy: Check every 30-60 minutes

• Surface Quality: Regular inspection sufficient

• Tool Condition: Normal wear, periodic replacement

• Machining Stability: Monitor machining process

• Regular quality inspection

• Standardize machining parameters

• Regular equipment maintenance

• Establish quality records

• Tool Cost: High (fast tool wear)

• Labor Cost: High (long machining time)

• Equipment Cost: High (high equipment wear)

• Use only when copper is absolutely necessary

• Mainly for high value-added products

• Need to optimize machining process to reduce costs

• Tool Cost: Low (long tool life)

• Labor Cost: Low (high machining efficiency)

• Equipment Cost: Low (low equipment wear)

• Very high cost performance

• Suitable for mass production

• Significant machining cost advantage

• Feed Control: Mainly use G01 linear feed

• Speed Control: Use S code to set appropriate speed

• Cooling Control: M08 continuous cooling

• Safety Considerations: Increase retract distance

• Feed Override: appropriate reduce feed override

• Spindle Override: Can appropriate increase spindle override

• Rapid Traverse: Normal setting

• Tool Compensation: Accurate tool compensation setting

• Feed Control: Can use higher feed rates

• Speed Control: High speed setting

• Cooling Control: Regular cooling setting

• Machining Efficiency: Optimize tool path for efficiency

• Feed Override: Normal or increased feed override

• Spindle Override: Normal setting

• Rapid Traverse: Normal setting

• Tool Compensation: Regular setting

• Spindle System: Frequently check spindle accuracy

• Cooling System: Regular cleaning of cooling system

• Guideway System: Strengthen guideway lubrication and cleaning

• Tool System: Frequently check tool holding system

• Daily Maintenance: Clean equipment, check cooling system

• Weekly Maintenance: Check spindle accuracy, lubricate guideways

• Monthly Maintenance: Comprehensive equipment accuracy check

• Regular Maintenance: Follow standard maintenance schedule

• Cooling System: Regular inspection and cleaning

• Tool System: Regular inspection

• Accuracy Check: Regular equipment accuracy check

• Daily Maintenance: Regular cleaning and inspection

• Weekly Maintenance: Lubrication and basic inspection

• Monthly Maintenance: Comprehensive maintenance inspection

• Chip Hazard: Ribbon chips Easy to get tangled

• Tool Risk: Fast tool wear, Easy chipping

• Temperature Risk: High machining temperature, Easy burns

• Personal Protection: Wear safety glasses, gloves

• Equipment Protection: Ensure safety guards are intact

• Operation Standards: Strictly follow operation procedures

• Emergency Stop: Familiarize with emergency stop button location

• Chip Hazard: Fragmented chips Easy splashing

• High Speed Risk: Safety risks of high-speed machining

• Equipment Risk: Regular machining safety risks

• Personal Protection: Standard protective equipment

• Equipment Protection: Normal safety protection

• Operation Standards: Standard operation procedures

• Environment Control: Maintain clean working environment

Start Material Selection

↓

Need high conductivity?

├─ Yes → Choose Copper

└─ No → Continue

↓

Need high strength?

├─ Yes → Choose Brass

└─ No → Continue

↓

Cost sensitive?

├─ Yes → Choose Brass

└─ No → Continue

↓

High surface quality requirement?

├─ Yes → Choose Brass

└─ No → Choose Copper

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This CNC machining specialized guide will help operators better understand and master the machining characteristics of copper and brass, improving machining efficiency and product quality.