Material removal rate in milling can be estimated using which of the following combinations?

• A. Spindle speed × chip load
• B. Depth of cut × cutting speed
• C. Width of cut × depth of cut × table feed per minute
• D. Tool diameter × feed per revolution

Answer: (C)

Material removal rate is the volume of material removed per unit time. In milling, that volume comes from the cross-sectional area of the cut times how fast the work advances under the cutter. The cross-sectional area is the width of cut times the depth of cut, and the rate of material removal also depends on how fast the table moves, i.e., the table feed per minute. Multiply these together: width of cut × depth of cut × table feed per minute gives the material removal rate.

The other options miss essential pieces. Spindle speed times chip load would give a feed-related value only if you also account for the number of teeth and rpm, and still wouldn’t include the width and depth of cut. Depth of cut times cutting speed lacks the actual feed and the width of cut. Tool diameter times feed per revolution doesn’t account for depth of cut or the cross-sectional area actually being removed.