Turning meets impact: what actually happens when a CNC lathe “hammers” material? In conventional CNC turning, a single-point cutting tool removes material through continuous chip formation under controlled feed and speed. But in certain operations—like interrupted cuts, knurling, pecking cycles, or when machining uneven stock—the tool experiences periodic impact loads that feel like “hammering.” These transient forces introduce high-frequency vibrations, known as chatter, which can degrade surface finish, accelerate tool wear, and even damage spindle bearings if not controlled. Key variables governing this behavior: * Cutting speed (surface feet per minute): Too high can amplify vibration modes; too low can cause built-up edge. * Feed rate: Influences chip thickness and force amplitude. * Depth of cut: Larger engagement increases force spikes during interruptions. * Tool geometry: Rake angle, nose radius, and coating affect chip flow and energy dissipation. * Workholding rigidity: P...