ISO/DIS 4545-3-2015 pdf free.Metallic materials一Knoop hardness test一 Part 3: Calibration of reference blocks.
This part of ISO 4545 specifies the method for the calibration of reference blocks to be used for the indirect
verification of Knoop hardness testing machines as specified in ISO 4545-2.
The method is applicable only for indentations with long diagonals  0,020 mm.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 376, Metallic materials — Calibration of force-proving instruments used for the verification of uniaxial testing machines
ISO 4287, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Terms, definitions and surface texture parameters
ISO 4545-1, Metallic materials — Knoop hardness test — Part 1: Test method
ISO 4545-2, Metallic materials — Knoop hardness test — Part 2: Verification and calibration of testing
3 Manufacture of the reference block
3.1 The block shall be specially manufactured for use as a hardness-reference block.
NOTE Attention is drawn to the need to use a manufacturing process which will give the necessary homogeneity, stability of structure and uniformity of surface hardnesS.
3.2 The reference block thickness shall be greater than twenty times the depth of indentation made with the certified test force.
3.3 The reference blocks shall be free of magnetism. It is recommended that the manufacturer ensure that the blocks, if made of steel, have been demagnetized at the end of the manufacturing process (before calibration).
3.4 The maximum deviation in flatness of the surfaces shall not exceed 0,005 mm /50mm,
3.5 The maximum error in parallelism shall not exceed 0,010 mmI5O mm.
3.6 The test surface shall be free from scratches which interfere with the measurement of the indentations. The surface roughness Ru shall not exceed 0,05 ijm for the test surface and the bottom surface shall be a finely ground finish or better. The sampling length L shall be 0,80 mm (see ISO 4287).ISO/DIS 4545-3 pdf free download.