The pencil method, particularly using the Starr Instruments TE-505, is a quick and straightforward technique for assessing the surface hardness of coatings, specifically in terms of their resistance to scratches from sharp edges and rough surfaces.

In the traditional pencil hardness test, pencils of varying hardness grades are moved over the coated surface at an angle of 45° to the horizontal, applying a force of 7.5N ±0.1N. The hardness is determined by observing the interaction between two pencils - one that produces a writing trace and another that produces a scratch. This method has been widely employed for its simplicity and effectiveness in evaluating the scratch resistance of coatings.

The TE-505 enhances the testing process based on the Wolff-Wilborn method, ensuring adherence to the specified force and angle. This device incorporates a guide that simplifies the testing procedure and eliminates manual influences on the pressure force. The Wolff-Wilborn test, originally performed with a test weight of 750 grams, now utilizes a test load of 7.5N. The Te-505 has adjustable weight blocks which feature three different angled pencil guides. These guides, based on their positioning, exert the appropriate test force on the pencil tip through the principle of leverage.

The advantages of this method lies in its ability to streamline the testing process, making it more user-friendly and precise. The three angled pencil guides provide versatility, allowing for the application of the prescribed test force according to the Wolff-Wilborn method. By minimizing manual influences on pressure force, this instrument ensures consistent and reliable results in assessing coating hardness and scratch resistance.