ISO 4545-3 is the ISO standard that specifies the method for calibrating the reference blocks used for the indirect verification of Knoop hardness testing machines, as specified in ISO 4545-2. The method applies only to indentations with long diagonals of 0.020 mm or more. The current edition is ISO 4545-3:2017, confirmed by ISO in its last review.
The standard is part of the ISO 4545 series, which also covers the Knoop test method and machine verification. Labs that check their Knoop testers indirectly depend on reference blocks calibrated to this part, so the block certificate is the link between their readings and the method. Labs usually confirm that the block certificate cites the right edition and the test force they use, and that their indentation sizes fall inside the range this part covers.
Reference blocks and accessories, such as our hardness test blocks, indenters and accessories, are used for the indirect verification of Knoop testers that work to the ISO 4545 series. If you need help matching ISO 4545-3 requirements to your parts or setup, contact our team.
