Metallic materials - Knoop hardness test - Part 2: Verification and calibration of testing machines (ISO 4545-2:2005); German version EN ISO 4545-2:2005— 23 стр.
Destructive tests on welds in metallic materials - Hardness testing of narrow joints welded by laser and electron beam (Vickers and Knoop hardness tests) (ISO 22826:2005)— 20 стр.