NF EN ISO 4545-1, A03-150-1 (10/2023)

This document specifies the Knoop hardness test method for metallic materials, for test forces ranging from 0.009 807 N to 19.613 N. This document specifies the Knoop hardness test for long diagonal length = 0.020mm. The use of this method to determine the Knoop hardness of smaller indentations is outside the scope of this document, as the results thus obtained would have high uncertainties due to the limitations of optical measurement and imperfections regarding the tip geometry. The Knoop hardness test specified herein is also applicable to metallic and other inorganic coatings, including electroplated coatings, electroless coatings, spray coatings and anodic coatings on aluminum. This document applies to measurements carried out perpendicular to the coated surface and to measurements carried out on cross sections, provided that the characteristics of the coating (flatness, thickness, etc.) allow an accurate reading of the diagonal of the indentation. This document does not apply to coatings with a thickness less than 0.007 mm when the test is carried out perpendicular to the surface of the coating. This document is not applicable to coatings with a thickness less than 0.020 mm when testing a cross section of the coating. ISO 14577-1 can be used for hardness determination from smaller indentations. A periodic verification method is specified for routine verification of the in-service testing machine by the user.
(Automatic translation from French)