The TQC Hardness Pen is a pocket instrument for testing the hardness and wear/scratch resistance of materials such as coatings, lacquers, plastics or related products. A tungsten carbide tip is drawn over the surface with a defined constant pressure. The pressure on the tip can be changed using the slide or by changing the spring. A visual mark on the surface after use of the TQC Hardness Pen indicates a fail of the surface hardness or wear/scratch resistance. Can be used on flat and curved surfaces.