CUTTING DATA
Feeds and Speeds: The Practical Basics
Spindle speed and feed rate connect tool diameter, cutting speed, chip load, and the number of cutting edges.
SHORT ANSWER
Start with the inputs you can verify
Spindle speed and feed rate connect tool diameter, cutting speed, chip load, and the number of cutting edges.
What the estimate means
Start from toolmaker data for the exact tool, work material, and operation.
Chip load is feed per tooth; feed rate depends on chip load, flute count, and spindle speed.
Where estimates go wrong
Machine rigidity, tool holding, coolant, engagement, and depth of cut can require conservative adjustments.
Keep the source measurements and assumptions with the result so another person can review or update the estimate later.
A practical workflow
- Identify the exact tool and material.
- Choose a supported cutting-speed and chip-load range.
- Calculate starting values, verify units, and prove them with a controlled test cut.