Customized Brass CNC Turned Parts

I. Core Material Properties and Application Advantages

(A) Performance Comparison of Mainstream Brass Alloys

(B) Driving Forces of Customization Requirements

1. Precision Machining Needs

 

• Dimensional accuracy: Shaft diameter tolerance ±0.005mm (e.g., aerospace plug pins), thread accuracy up to ISO 4H/6g grade.
• Surface roughness: Ra≤0.8μm (medical catheter connectors), mirror polishing up to Ra≤0.2μm.

 

2. Functional Performance Requirements

 

• Electrical conductivity: Contact resistance ≤5mΩ (electronic connectors) for high-frequency signal transmission.
• Pressure bearing capacity: Hydraulic components withstand ≥10MPa, leakage rate ≤1×10⁻⁹ mbar·L/s (helium mass spectrometer detection).

 

3. Environmental Adaptability

 

• Corrosion resistance: Neutral salt spray test ≥720 hours without rust (outdoor hardware).
• Temperature range: Dimensional stability ≤±0.01% in -40℃~120℃ environment (automotive sensor components).

II. Analysis of Four Core Processing Technologies

(A) CNC Turning: High-Precision Rotational Part Machining

• Technical Advantages
  • 5-axis 联动 CNC machining centers achieve complex surface one-step forming (e.g., spiral gears, eccentric shafts) with accuracy up to ±0.005mm.
  • Supports micro-part machining (diameter ≥0.5mm), suitable for precision fields like watch movements and medical micro-catheters.
• Process Parameters
  • Spindle speed: 2000-8000rpm (brass bar stock), feed rate 0.05-0.3mm/r.
  • Tool selection: PCD diamond tools (surface roughness Ra≤0.4μm), carbide tools (wear-resistant machining).
  • Cooling system: Water-soluble cutting fluid reduces temperature rise, ensuring thermal deformation ≤0.003mm.

(B) Surface Treatment Technologies

(C) Composite Machining Technologies

• Milling Integration
  • Turn-mill composite machining centers achieve one-step forming of radial holes, keyways, etc., with positional accuracy ±0.01mm.
  • Processing efficiency of polygonal shafts increased by 50%.
• Thread Machining
  • Whirlwind milling for high-precision threads (pitch accuracy ±0.002mm), surface hardness increased by 20%.
  • Supports customization of M1-M30 metric threads and UN/BSW imperial threads.

(D) Inspection and Quality Control

• Precision Measurement
  • Coordinate Measuring Machine (CMM) detects geometric tolerances (roundness ≤0.002mm, perpendicularity ≤0.005mm).
  • Laser diameter gauge monitors machining dimensions in real time with 100 times/second data acquisition.
• Nondestructive Testing
  • Eddy current flaw detection for internal cracks (minimum detection size ≥0.1mm).
  • Air tightness test (50kPa pressure maintained for 10 minutes, leakage ≤5ml/min).

III. Full-Process Customization Solutions

(A) Design and Material Engineering

1. Multi-Dimensional Design Support

 

• Structural Optimization
  • Stress distribution analyzed via ANSYS simulation, optimized fillet radius R≥0.5mm for stepped shafts, fatigue life increased by 40%.
  • Progressive turning for thin-walled parts (wall thickness ≥0.8mm), deformation ≤0.008mm.
• Functional Customization
  • Elastic contact structure for conductive components, insertion life ≥10,000 cycles (contact force decay ≤15%).
  • Passivation treatment for medical components, heavy metal leaching ≤0.1ppm (compliant with USP Class VI standard).

 

2. Precise Material Selection

 

• Electronics: H70 brass + gold plating (conductivity ≥26%IACS, contact resistance ≤3mΩ).
• Marine Engineering: HSn62-1 tin brass (seawater corrosion resistance, salt spray test ≥1200 hours).
• High-End Decoration: HPb59-1 leaded brass + mirror polishing (surface hardness ≥130HV, glossiness ≥85GU).

 

3. Pre-Processing Technology

 

• Material annealing: Stress relief at 520℃ for 1 hour, machining deformation rate ≤0.02%.
• Tool coating: TiAlN coating reduces friction coefficient to 0.05, tool life extended by 3 times.

(B) Production and Quality Control

1. Flexible Manufacturing Capability

 

• Rapid Prototyping
  • 3D printed brass samples delivered in 24 hours, CNC first article processing cycle 3 days.
  • Supports single-piece customization (e.g., aerospace prototypes), minimum order quantity 1 piece.
• Mass Production
  • Automated production lines with gantry robots, single machine daily capacity 5000 pieces (standard shaft parts).
  • Intelligent scheduling system optimizes delivery time, batch order cycle reduced by 20%.

 

2. Comprehensive Inspection System

 

• Mechanical Properties
  • Tensile test: Yield strength ≥200MPa (ISO 6892 standard), elongation ≥30%.
  • Torque test: Connecting components bear ≥50N·m (GB/T 3098.1 standard).
• Environmental Performance
  • Thermal cycling: -40℃~80℃ for 50 cycles, dimensional change rate ≤0.03%.
  • Wear test: Friction wear ≤0.005mm (100,000 cycles, ASTM G99 standard).
• Certification Support: Provides ISO 9001, RoHS, REACH and other certification reports, compliant with EU/North American market access requirements.

IV. Multi-Scenario Application Solutions

(A) Electronics and Communications

• High-Frequency Connectors
  • H65 brass turned pins with 3μm gold plating, insertion loss ≤0.1dB (10GHz band).
  • Tolerance control ±0.003mm, adapted to high-density PCB spacing requirements.
• Relay Components
  • Tin-phosphor bronze spring sheets (conductivity ≥15%IACS), service life ≥100,000 cycles, contact reliability ≥99.9%.

(B) Medical Devices

• Surgical Instrument Shafts
  • HPb59-1 leaded brass + passivation treatment, surface roughness Ra≤0.4μm, compliant with ISO 13485 sterilization requirements.
  • Stepped shaft fit accuracy H7/g6 ensures smooth opening/closing without jamming.
• Medical Catheter Connectors
  • Thin-walled tube (wall thickness 1.2mm) machining accuracy ±0.005mm, airtightness test leakage rate ≤1×10⁻¹⁰ mbar·L/s.

(C) Automotive and Aviation

• Fuel System Components
  • HSn62-1 tin brass oil pipe connectors, fuel corrosion resistance (volume change rate ≤2%), pressure resistance ≥15MPa.
  • Thread accuracy 6H/6g, adapted to ISO 8434-1 standard interfaces.
• Aviation Instrument Gears
  • Brass worm and worm gear, tooth surface roughness Ra≤0.8μm, transmission efficiency ≥90%, vibration resistance (10-2000Hz, 5g acceleration).

(D) High-End Decoration and Luxury Goods

• Watch Components
  • H70 brass crown with mirror polishing Ra≤0.2μm, 2μm rose gold plating, salt spray test ≥800 hours.
  • Engraving process achieves 0.05mm depth LOGO with accuracy ±0.01mm.
• Furniture Hardware
  • Brass hinge cores with aged treatment simulation ≥95%, opening/closing life ≥50,000 cycles, noise ≤30dB.

V. Technology Selection Guide