Ra Rq Rz Roughness values explained

Besides alloying composition, surface characteristics have a strong influence on the corrosion resistance of a stainless steel product. In decorative applications, where appearance is critical, poor understanding of surface properties can be a source of discussions between specifiers and fabricators.
A new concise Euro Inox publication explains the roughness measures Ra, Rz and Rq and addresses their respective advantages and limitations. Common grit sizes of abrasives are associated with typical roughness values of stainless steel surfaces. The definitions of finishes in the standards EN 10088-2 and ASTM A 480/480 M, although they are mostly descriptive, in some cases also include Ra values. The text also raises awareness of important details of notation: for instance, “Ra ≤ 0.5 µm” does not have the same meaning as “Ra max 0.5 µm”. The seven-page paper can be downloaded from http://www.euro-inox.org/pdf/map/RoughnessMeasurement_EN.pdf.

Published 19/12/2014 10:16:19 Last Modified 19/12/2014 10:18:48

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