When the chip load drops below the edge radius of the tool, the edge plows and burnishes the surface instead of shearing a chip. Rubbing makes heat, squeal and glazed surfaces, wears the tool fast and work-hardens stainless and nickel alloys. The fix is almost always more feed, a sharper tool or both, which surprises newcomers who try to slow down instead.
It's rubbing, not cutting, listen to it squeal, bump the feed up and quit babying it.
Also heard as
- rub
- plowing
Related terms
Chip load
The thickness of material each cutting edge takes per revolution, also called feed per tooth.
Work hardening
Hardening of a metal surface by plastic deformation, which makes the next cut much harder on the tool.
Chatter
Self-sustaining vibration between tool and work that screams, leaves a wavy pattern and kills tools.
Feeds and speeds
The spindle speed and feed rate chosen for a cut, set from material, tool and machine.