Width of cut

Width of cut (also called radial depth of cut or stepover) is how far a milling tool engages the material radially, as a proportion of its diameter. Together with axial depth of cut, it determines the material removal rate and the cutting forces the tool experiences in a given pass.

Why width and depth of cut are chosen together, not independently

A wider engagement removes more material per pass but increases heat concentration on the cutting edge and cutting force, which is why high-efficiency roughing strategies often use a smaller width of cut paired with a larger depth of cut, rather than the reverse.

Where width of cut is set

Not on the drawing; it's a programming and toolpath-strategy parameter, chosen based on tool, material and machine capability rather than specified directly by part requirements.

Common mistakes

Assuming a wider width of cut is always more efficient; heat concentration at high radial engagement can shorten tool life faster than the time saved by fewer passes.

Is width of cut the same as depth of cut?

No, depth of cut is the axial engagement (how deep); width of cut is the radial engagement (how much of the tool diameter is used sideways).

What is stepover?

Another common name for width of cut, particularly in the context of finishing passes and surface toolpaths.

Why do high-efficiency strategies use a smaller width of cut?

Because a smaller radial engagement spreads heat over more of the cutting edge, allowing a larger axial depth without shortening tool life.