CNC Cutting Parameters Guide
Correct speeds and feeds are critical for part quality and tool life. This guide provides starting parameters for common materials.
Cutting Speed Recommendations
| Material | Carbide (SFM) | Rough DOC | Finish DOC |
|---|---|---|---|
| Aluminum 6061 | 800-1500 | 3-8mm | 0.2-0.5mm |
| Mild Steel 1018 | 400-800 | 2-5mm | 0.15-0.4mm |
| Stainless 304 | 200-400 | 1-3mm | 0.1-0.3mm |
| Titanium Ti-6Al-4V | 150-300 | 1-2mm | 0.1-0.25mm |
| Brass | 800-1200 | 3-6mm | 0.2-0.5mm |
Chip Load
Feed rate (mm/min) = RPM × Chip load (mm/tooth) × Flutes. Typical chip loads: aluminum 0.08-0.20, mild steel 0.05-0.12, stainless 0.03-0.07, titanium 0.025-0.05.
Climb vs Conventional
Climb milling: Tool rotation same as feed direction. Better finish, less heat, lower forces. Default for rigid setups. Conventional: Used for work-hardened surfaces (castings/forgings) and machines with backlash.
Coolant Strategy
- Flood: 5-15% soluble oil for most metals
- Through-spindle: Required for deep hole drilling (>3xD), 20-40 bar
- MQL: Covers Al and cast iron. 90%+ coolant reduction
- Dry: Cast iron and some plastics with air blast
Tool Wear Limits
Flank wear limits: finishing tools 0.15mm, roughing tools 0.3mm, drills 0.1mm corner wear. Re-sharpen before reaching limits.