BYK-Gardner 5800 Wolf-Wilburn Pencil Hardness Tester

The purpose of scratch hardness tests is to determine the resistance of coating materials or lacquers to scratch effects on the surface. This test is of particular value for furniture or vehicle lacquers, but is also a useful aid in the development of synthetic resins or other film forming materials. Generally, scratch hardness is measured by moving a sharp object under a known pressure over the test surface. The result may either be the value of the pressure required to scratch through the test material if a scratching tool of constant hardness is used, or the hardness of the scratching tool is varied while constant pressure is applied.