kromming

Kromming is the Dutch term for deformation characterized by bending, warping, or distortion that causes an object to lose straightness, flatness, or its intended geometry. The word derives from krom, meaning curved, with the suffix -ing forming a noun.

In manufacturing and engineering, kromming describes deviations from design specifications, such as a metal plate that is not flat, a wooden board with a warped edge, or a plastic part with curvature. It can arise during fabrication, processing, or in service due to internal stresses, temperature changes, humidity, or uneven loading.

Measurement and quality control rely on comparing surfaces or geometries with reference dimensions using tools such as straightedges, dial indicators, surface plates, or profilometers. Tolerances are defined in technical drawings to determine acceptable levels of kromming for a given component or assembly.

Causes of kromming include residual stress from forming or welding, nonuniform cooling or drying, uneven moisture content, improper fixturing, and abnormal gripping or mounting during processing. Environmental conditions and long-term service loads can also contribute to progressive warping.

Prevention and correction involve approaches such as stress-relieving heat treatments, machining or planing to restore straightness or flatness, and improved fixturing and process control to prevent recurrence. In addition to physical contexts, kromming can be used metaphorically to describe distortion or bias in plans, data, or interpretations when conditions are not ideal.

See also: warping, distortion, curvature.