The scratch test (also known as scratch hardness test or scratch resistance test) is a method used to evaluate the hardness and wear resistance of a material by observing its response to a controlled, single-point contact with a sharp, rigid indenter that moves along its surface. The test involves applying increasing force to an indenter (usually a diamond or hard material) as it is dragged across the material’s surface, creating a scratch. The properties of the scratch, such as the depth, width, and the material’s ability to resist or deform under the applied force, provide valuable information about the material’s surface hardness and other mechanical properties like adhesion, abrasion resistance, and coating performance.