100R Series

Tool 100Rm040A

Large roughers take heat and wear differently than smaller tools. The cutting forces scale up, the chip loads get heavier, and tool life becomes the limiting factor in high-volume material removal. This 4" diameter rougher in the 100R Series carries TiAlSiN coating specifically for that reason. The aluminum in the coating forms a protective oxide layer at cutting temperature, extending tool life when you're pushing serious chip loads through steel, iron, titanium, and nickel alloys.

The chipbreaker geometry along all four flutes handles the increased chip volume that comes with a 4" cutting diameter.
You're not dealing with long stringy chips wrapping around the spindle or packing the flutes.
The 0.1" chamfer strengthens the cutting edge against the higher impact loads these larger tools see in heavy roughing operations.
It leaves a rough surface.
That's the point.