scope:

This International Standard specifies a test method for determining under defined conditions the resistance of a single coating or a multi-coat system of paint, varnish or related product to penetration by scratching with a scratch stylus which is loaded with a test force. Penetration of the scratch stylus is to the substrate, except in the case of a multi-coat system, where the scratch stylus may penetrate either to the substrate or to an intermediate coat. The method is intended for application as follows: a) either as a "pass/fail" test, by testing with a single specified load applied to the scratch stylus to assess compliance with a particular specification; or b) by applying increasing loads to the scratch stylus to determine the minimum load at which the coating is penetrated.