Design Nomenclature / Physical Model Making

Feed and speed

Also called feeds and speeds, surface speed, chip load, SFM

The pair that governs every rotating cut: how fast the tool turns and how fast it advances. Together they set chip thickness. Too slow a feed rubs and burns the edge off the tool; too fast deflects or snaps it. Most shop failures blamed on a dull cutter are a feed-and-speed error that dulled it.

One cutter drawn three times at the same spindle speed with rising feed. At low feed the flute rubs and the chip is a smear; at correct feed a comma-shaped chip of measurable thickness lifts clear; at high feed the chip is thicker than the flute can clear and the tool is shown deflecting.

In practice

Beginners raise speed and lower feed because it sounds safer. It is the combination that kills tools fastest — the cutter rubs instead of cutting.

How this term connects

ChatterCNC millingConventional cutMillingTear-outToolpathTurningFeed and speed
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