Research Area

Primer & Chemical Surface Treatment

Buchholz Hardness Test
(Indentation Resistance)

The Buchholz hardness test is used to determine the indentation resistance aB of polymeric coating materials (such as varnishes).
To determine the Buchholz hardness, the hardness tester is placed on the horizontal surface for 30 s. In this position the indenter, a circular knife, leaves an indentation.

The length of the indentation is measured with a microscope (20× magnification). Based on this length, a comparison table is used to determine the indentation resistance aB. A more comprehensive examination of the indentation is possible, for example, using a 3D microscope.

This method can only be used for plastically deformable coatings such as paints, varnishes and fillers.

The test is carried out according to DIN EN ISO 2815.

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BYK Gardner GmbH


PH - 5825

Dr. Joerg Leuthaeusser

Head of Department
Primer and Chemical Surface Treatment

Phone: +49 3641 2825 48