Pencil Hardness Test
A pencil hardness test is a type of evaluation method that is performed to determine the hardness of a material, typically coating materials. To perform a pencil hardness test, graphite pencils of varying hardness are moved across a coating's surface. Its hardness relative to the graphite pencils is determined by the softest pencil that will leave a scratch on the surface of the coating.
The test is popular, partly because it is a portable process.
The pencils are small, and if a mechanical holder is used to carry the pencils, then it too is often compact and readily portable. Another reason is because it is simple. All that is required is a set of pencils and a person to drag the pencil across the coating material. These reasons make a pencil hardness test ideal for testing coatings because it can be done quickly in the field.