Full-width slots (cutting at 100% of tool diameter) load every tooth more than a normal side-milling pass. This scales a normal feed rate down by a slotting reduction factor.
Normal feed = RPM x Chip Load x Flutes. Slotting feed = Normal feed x (reduction % / 100). 50 to 70% is a common starting range for full-width slots; lower it further for long-reach or weak setups.
How it works
At full width of cut, every tooth is fully engaged with no relief on either side, which raises cutting forces and heat versus a partial-width pass. Reducing programmed feed compensates without changing chip load formulas elsewhere.
FAQ
Is there one correct reduction percentage? No, it depends on tool, material, and rigidity. Treat the default as a starting point and adjust from test cuts.
Related Guides
CNC Calculators · Feed Rate Calculator · Chip Load Calculator