Milling removes material with a rotating cutter that carries multiple cutting edges. Unlike turning, each tooth usually enters and leaves the cut, so the process is inherently interrupted.

If a cutter has $z$ teeth, rotates at $N$ rev/min and advances at table feed $F$, the feed per tooth or chip load is

$$f_z=\frac{F}{zN}.$$

For example, a four-flute cutter at $N=3000$ rev/min and $F=600\ \mathrm{mm/min}$ has

$$f_z=\frac{600}{4\times3000}=0.05\ \mathrm{mm/tooth}.$$

Chip load is more informative than table feed alone because each cutting edge experiences the material individually.

In peripheral milling, teeth cut mainly with the cylindrical surface of the tool. In face milling, edges near the cutter face generate the machined plane. End mills can combine peripheral and end cutting to create slots, pockets and contours.

The direction of feed relative to cutter rotation distinguishes conventional and climb milling. This changes how chip thickness develops through each tooth engagement and affects force direction, backlash sensitivity and surface behavior.

Milling performance depends on engagement, chip evacuation, tool stiffness, workholding and vibration. Because cutting force rises and falls as teeth engage, poorly chosen conditions can excite chatter even when average spindle power is adequate.