Overcutting

Overcutting is the removal of more material than specified by a design, resulting in a feature that is larger or deeper than intended. It can occur in any fabrication process that uses subtractive cutting or shaping, including machining, milling, turning, drilling, and routing. In many contexts, overcutting means the cutting path extends beyond the desired boundary, which can lead to dimensional inaccuracy, poor fit, or compromised structural integrity.

In machining, overcutting commonly manifests as corner overcuts or depth overcuts where pockets, slots, or shoulders exceed their intended dimensions. Causes include incorrect toolpath generation, radius compensation errors in CAM software, tool deflection under load, worn or undersized tools, excessive stock removal, improper feeds and speeds, and machine issues such as backlash or thermal growth. Consequences range from poor dimensional tolerances and rough surface finishes to interference with mating parts and the need for rework or part rejection.

Prevention and mitigation strategies focus on accurate tool data, validated toolpaths, and controlled machine behavior. Actions include verifying tool diameter and radius compensation, running CAM simulations, using stock-aware planning, applying finishing passes, and selecting appropriate feeds and speeds to reduce deflection. Regular maintenance, alignment checks, and precise measurement of finished parts with appropriate inspection methods help detect overcutting early.

In dentistry and some other fields, overcutting refers to removing more material than necessary during a procedure or preparation, which can weaken structure or introduce sensitivity. Prevention relies on precise instruments, depth control, and careful measurement to preserve as much of the original material as possible.