CNC Brass Machining

Brass has become a commonly used non-ferrous metal material in CNC machining due to its excellent mechanical properties, corrosion resistance, and aesthetics. CNC (Computer Numerical Control) machining technology can achieve complex shape manufacturing and precise dimensional control of brass parts through high-precision automation control. The following analysis will be conducted from the aspects of material characteristics, processing technology, application scenarios, and precautions.

1、 Characteristics and advantages of brass material

Physical and chemical properties

Composition: Brass is an alloy of copper and zinc, commonly used in grades such as C26000 (H62) and C36000 (free cutting brass). The zinc content affects strength and workability.

Mechanical properties:

Moderate hardness (HB 60-120), easy to cut and not prone to fracture.

Good ductility, suitable for secondary processing such as bending and stamping.

Corrosion resistance: superior to ordinary carbon steel, stable in humid or weak acid-base environments.

Conductivity and thermal conductivity: The conductivity is about 28% of pure copper, and the thermal conductivity is excellent, making it suitable for heat dissipation components.

Processing advantages

Cutting performance: Self lubricating properties reduce tool wear and are suitable for high-speed machining.

Surface quality: After processing, the surface smoothness is high, which can reduce subsequent polishing processes.

Weldability: Some brass (such as C27000) has good weldability and is suitable for complex structures.

2、 CNC brass machining process flow

Process Selection

Milling: Suitable for complex shapes such as flat surfaces, grooves, and contours, it is recommended to use hard alloy cutting tools.

Turning: Used for shaft and sleeve parts. When turning brass, chips are easily broken and smoothly discharged.

Drilling/tapping: When tapping brass, attention should be paid to lubrication to avoid thread sticking to the tool.

Electric discharge machining (EDM): suitable for high-precision, complex cavities (such as mold inserts).

optimization

Cutting speed: 80-300 m/min is recommended for Milling, and 100-500 m/min is recommended for turning (adjusted according to the grade).

Feed rate: 0.05-0.3 mm/rev, can be appropriately increased for rough machining.

Cutting depth: 1-3 mm for rough machining and 0.1-0.5 mm for precision machining.

Coolant: Water soluble cutting fluid can effectively reduce temperature and minimize tool wear.

Typical Process Flow Example

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1. Material preparation → 2 Rough machining (leaving a margin of 0.2-0.5mm) → 3 Semi precision machining →

4. Precision machining (dimensional tolerance ± 0.01 mm) → 5 Deburring → 6 Surface treatment (such as nickel plating, passivation)

3、 Application scenarios and cases

Main application areas

Electronic and electrical components: connectors, terminals, heat sinks (utilizing thermal conductivity).

Instrumentation: Precision gears, valve bodies, sensor housings (requiring high precision).

Decoration and hardware: handles, lighting accessories, artistic ornaments (utilizing aesthetics).

Fluid control: valves, pump bodies, pipe joints (corrosion-resistant+easy to process).

classic case

Case 1: Precision gears

Material: C36000 brass

Process: CNC turning+gear milling

Accuracy: Pitch error<0.02 mm, surface roughness Ra 0.8

Case 2: Heat dissipation fins

Material: C26000 brass

Process: CNC milling+surface anodizing

Effect: Heat dissipation efficiency is improved by 30%, and the weight is 15% lighter than aluminum parts

4、 Processing difficulties and solutions

frequently asked questions

Fast tool wear: Lead in brass (such as C36000) is prone to adhere to the tool, leading to a shortened lifespan.

Surface oxidation: Local oxidation caused by high temperature during processing, affecting the appearance.

Dimensional deformation: Thin walled parts are prone to deformation due to residual stress release after processing.

Solution

Tool selection: Use TiAlN coated tools to improve wear resistance; Adopting a sharp edge design to reduce cutting force.

Cooling control: High pressure coolant flushes chips and reduces temperature; Optimize cutting parameters to reduce heat accumulation.

Process optimization: Thin walled parts are processed symmetrically and the excess is removed step by step to reduce stress concentration.