Körnung

Körnung is a German term used in several technical fields to describe the size of grains or particles in a material, surface finish, or sediment. It broadly denotes granularity or fineness and is applied in contexts ranging from abrasive media to microstructural features.

In abrasive technology, Schleifkörnung refers to the particle size of abrasives used for grinding, sanding, or polishing. Coarser Körnung has larger particles and removes material quickly, while finer Körnung uses smaller particles to produce smoother finishes. Grit sizes are typically expressed as numbers, with higher numbers indicating finer grains. Common examples range from coarse grits around 40–60 up to very fine grits above 2000, depending on the tool and material.

In metallurgy and materials science, Körnung also describes the grain size of a polycrystalline material’s microstructure. The size of individual crystals (grains) influences mechanical properties; generally, finer grains improve strength and toughness through grain boundary strengthening. Grain size is controlled by heat treatment, deformation, and recrystallization, and is often characterized by optical microscopy and standard grain size metrics.

In geology and sedimentology, Körnung denotes the size distribution of sediment particles, from clay and silt to sand, gravel, and cobbles. The grain-size distribution informs interpretation of transport energy, depositional environment, and porosity.

In ceramics and powder processing, Körnung describes particle size within powders or suspensions used for shaping, sintering, or coating processes. Across disciplines, Körnung is a fundamental descriptor of material texture that influences performance and behavior.