CNC (Computer Numerical Control) machining is a subtractive manufacturing process where pre-programmed software controls the movement of cutting tools. It is the most versatile precision manufacturing method available.
3-Axis Machining — Most common. X, Y, Z linear axes. Perfect for flat surfaces and simple features.
4-Axis Machining — Adds a rotary (A) axis. Can machine cylindrical features in one setup.
5-Axis Machining — Three linear + two rotary axes. Can machine complex free-form surfaces (mold cavities, turbine blades, medical implants) in a single setup.
Spindle speeds: Standard VMC 8,000-15,000 rpm; High-speed 30,000-50,000 rpm
P20 Tool Steel — Cutting speed: 100-180 m/min, Feed per tooth: 0.1-0.3mm
S136H Stainless — 100-150 m/min, 0.08-0.2mm/ tooth
7075 Aluminum — 400-800 m/min, 0.1-0.4mm/ tooth
H13 Hot Work — 70-120 m/min, 0.08-0.2mm/ tooth
Copper (red) — 200-400 m/min, 0.1-0.3mm/ tooth
Brass — 200-500 m/min, 0.1-0.3mm/ tooth
These are reference ranges — exact speeds depend on machine rigidity, tool overhang, and coolant conditions.
Face Mill (Φ50-200mm) — Flat surfaces, large area material removal
End Mill (Φ1-20mm) — Slots, profiling, contours — the workhorse tool
Ball Nose End Mill — 3D surface finishing (mold cavities)
Drill — Hole making (center drill + twist drill)
Reamer — Precision holes (tolerance to H7, IT7) for fitting
Coating selection:
TiAlN (Titanium Aluminum Nitride) — High heat resistance, for hardened steel, high-speed cutting
TiN (Titanium Nitride) — General purpose steel
DLC (Diamond-Like Carbon) — Abrasive materials, aluminum, copper
AlTiN (Aluminum Titanium Nitride) — Superior high-temperature performance
Roughing: ±0.1-0.2mm tolerance, Ra 6.3-12.5μm
Semi-finishing: ±0.05mm tolerance, Ra 3.2-6.3μm
Finishing: ±0.01-0.02mm tolerance, Ra 0.8-1.6μm
Super-finishing: ±0.005mm tolerance, Ra 0.2-0.4μm
Note: Chinese CNC shops typically quote to ±0.05mm as 'standard precision'. Ask explicitly for 'precision machining' (±0.01mm) if required — this may add 15-30% to the price.
China has an estimated 4+ million CNC machines in operation, the largest installed base globally. The Pearl River Delta (Guangdong) alone has tens of thousands of CNC job shops.
Typical CNC shop hourly rates in China (2026):
• 3-axis VMC: ¥50-120/hr
• 4-axis: ¥80-180/hr
• 5-axis: ¥150-400/hr
• High-speed engraving: ¥60-150/hr
• CNC lathe (turning): ¥40-100/hr
Price factors: Brand of machine (Haas/DMG vs domestic), tolerance requirement, material, quantity, and surface finishing needs.
Most Chinese shops accept STEP/IGS/STP files for quoting and provide DFM feedback within 24 hours.