What is chip load?

• A. The amount of material removed by each tooth per revolution or per tooth.
• B. The speed of the spindle.
• C. The total depth of cut per pass.
• D. The feed rate of the table.

Answer: (A)

Chip load is the amount of material removed by each tooth during cutting. In milling, each tooth removes a small chip, and the chip load is the thickness of that chip, usually expressed in inches per tooth (or millimeters per tooth). It’s a per-tooth measure that depends on the overall feed rate, spindle speed, and the number of cutter teeth; you can think of it as how much metal each tooth takes off with every pass as the cutter spins.

A practical way to relate the numbers is f_z = feed rate / (rpm × number of teeth). This concept matters because the chip load influences cutting forces, heat generation, and tool wear. If the chip load is too high, you risk tool breakage or a rough finish; if it’s too low, you may get rubbing, built-up edge, and inefficient material removal.

The other terms refer to different parameters: spindle speed is the rotation rate, total depth of cut per pass is how deep the cutter goes into the work in one pass, and the feed rate of the table describes how fast the workpiece moves, not how much each tooth removes.