Rzértékekkel

Rzértékekkel is a term used in engineering and manufacturing to refer to analyses, specifications, or quality-control practices that rely on the surface roughness parameter Rz. In surface metrology, Rz is one of the standard metrics used to describe the vertical deviations of a real surface from an ideal plane and is commonly employed alongside other parameters such as Ra.

Rz refers to the mean height of the roughness profile, calculated as the average of the five largest peak-to-valley heights measured along the evaluation length. In traditional profilometry, the evaluation length is subdivided into five sampling lengths, and the maximum peak-to-valley height within each length is determined; these five values are then averaged to obtain Rz. The result is typically expressed in micrometers.

Measurement and interpretation are performed with profilometers or stylus instruments, which physically trace the surface or use optical methods. Important factors in obtaining Rz values include the sampling length, the cut-off filter, the measurement direction, and the instrument’s stylus geometry. Different standards (for example ISO 4287 for profilometry and ISO 25178 for areal measurements) dictate how Rz should be measured and reported, and how it relates to other roughness descriptors.

Applications of Rz értékekkel include setting manufacturing tolerances, selecting appropriate finishing processes, and assessing surface quality for functional mating, wear resistance, and lubrication performance. While Rz provides a straightforward indication of peak-to-valley roughness, it is sensitive to measurement length and direction, and its usefulness is often complemented by other parameters such as Ra, Rq, or areal equivalents when evaluating complex textures.

See also: surface roughness, Ra, profilometry, ISO standards.