ASTM D3363-22 is a standard test method for measuring the Hardness of organic coatings on the surface of hard substrates such as metals, usually by using pencil lines with different Hardness. This method is widely used in the Coatings industry to evaluate the Hardness and curing of coatings, especially during manufacturing and quality control processes. Using pencils from the same manufacturer and batch can improve the reproducibility of test results, thus enhancing the Reliability of inter-laboratory comparisons. However, using pencils from different manufacturers or batches may cause differences in results. This standard does not apply to Coatings on softer substrates such as wood. If this test method is to be used as the basis for the purchase agreement, it shall be carried out with an agreed set of referee pencils to ensure the accuracy and conformity of the test.