ISO 19252:2008 specifies a method for determining the scratch properties of plastics under defined conditions. The method involves making a scratch by moving a hard instrument (scratch tip) of specified geometry under specified conditions of load and speed across the surface of a test specimen and then assessing the result.
The method is used to investigate the behaviour of specified types of specimen under the scratch conditions defined and for classifying the type of scratch of specimens within the limitations inherent in the test conditions. It can also be used to determine comparative data for different types of material by means of a so‑called scratch map in which the types of scratch behaviour for each set of test conditions of test load and test speed are determined using the basic method of constant-load testing, and also by means of the so‑called critical normal load determined using an alternative method of linearly increasing load testing.
The method is suitable for use with uncoated and unlacquered thermoplastic moulding materials and thermosetting moulding materials.
The method specifies the preferred dimensions for the test specimen and the preferred scratch-tip geometry.