Poleringsgrad

Poleringsgrad, or polishing grade, describes the degree of smoothness a surface attains after finishing. In many industries it combines qualitative descriptors such as rough, semi-polished, polished, and mirror with quantitative measurements of surface texture. The most common indicators are roughness parameters, notably Ra (arithmetic mean roughness) and Rz (mean peak-to-valley height). Poleringsgrad influences how a surface interacts in terms of contact, wear, corrosion, optics, and tactile perception, making it a key parameter for quality and performance.

It is achieved through a controlled sequence of abrasive steps using progressively finer abrasives, polishing pastes, and sometimes lubricants. The final grade depends on abrasive size, applied pressure, dwell time, stroke pattern, and the material’s hardness and microstructure. Different materials—metals, ceramics, polymers, and composites—respond differently, so the target poleringsgrad is defined for the specific material and application.

Measurement is typically performed with contact profilometry, non-contact optical profilometry, or interferometry. Ra is the standard reference, but Rq, Rz and higher-order statistics may be used for more detail. Many industries rely on finish codes, reference samples, or standardized procedures to specify and verify the desired poleringsgrad. Calibration and documentation are essential for repeatability.

Applications include optics and electronics, where higher poleringsgrad reduces scattering and improves reflectivity and solderability; in dentistry, enamel or restorative surfaces are finished to minimize plaque buildup and irritation.