Standard ASTM D3363-2005 "Standard Test Method for the Determination of Film Hardness by Pencil Test Method" Rapid and cost-effective hardness testing on the surface of a coating by using a pencil lead known to Hardness. This method is particularly suitable for evaluating the Hardness of organic coatings, especially in laboratory research and development and production control processes. The test results provide an important reference for evaluating coating curing and Hardness, and can help to formulate suitable Coating selection and application conditions. The standard describes in detail the steps and conditions of testing, including coating scratch with pencils of different Hardness, and then determining the Hardness grade of the film according to the scratch.