ISO 20567-1-2017 "Determination of Stone Strike Resistance of Paints and varnish coatings, Part 1: Multiple Impact Testing" is an international standard designed to assess the resistance of automotive and Miscellaneous coatings to the impact of cold iron grit. These tests simulate damage to coatings from grit, road metals, etc., for example resulting in coating peeling or delamination. This standard describes in detail the method of multiple Impact testing, which is suitable for assessing the durability of coatings under real-world conditions of use. ISO 20567-1 has been technically revised to include a Particle size distribution table for grit materials and instructions for using an actual pressure gauge. In addition, the standard provides recommended procedures for calibrating equipment to ensure accuracy and comparability of test results.