Feed Rate
The speed at which the cutting tool advances along the workpiece, typically measured in mm/min (millimeters per minute) or IPM (inches per minute) in CNC machining.
Feed rate is one of the most critical parameters in CNC machining. It directly affects surface finish quality, tool life, and cycle time.
How Feed Rate is Calculated
The feed rate formula for milling is:
F = N × fz × z
Where:
- F = Feed rate (mm/min)
- N = Spindle speed (RPM)
- fz = Chip load per tooth (mm/tooth)
- z = Number of flutes/teeth
Impact on Machining
- Too high: Excessive tool wear, poor surface finish, risk of tool breakage
- Too low: Rubbing instead of cutting, work hardening (especially in stainless steel), wasted time
- Optimal: Clean chip formation, good surface finish, efficient material removal
Use our Feed & Speed Calculator to find the optimal feed rate for your specific material and tool combination.
Related Terms
Spindle SpeedChip LoadCutting SpeedMaterial Removal Rate