Which ASTM test for scratch resistance?

The ASTM test for scratch resistance is the ASTM D5178 Standard Test Method for Mar Resistance of Organic Coatings. This test method is used to evaluate the mar resistance of organic coatings, including paints, varnishes, and lacquers.

The ASTM D5178 test involves using a stylus or pointed object to create a scratch on the surface of the coated sample, and then visually examining the scratch to determine its depth and width. The test is typically performed using a series of stylus tips of increasing hardness, ranging from 2B to 9H on the graphite pencil hardness scale.

The ASTM D5178 test can provide valuable information about the scratch resistance of coatings, particularly in applications where the coating may be subjected to mechanical or abrasive forces. It is commonly used in industries such as automotive, aerospace, and consumer products to evaluate the durability and performance of coatings and finishes.

It is worth noting that while the ASTM D5178 test is specifically designed for coatings, there are other ASTM tests that can be used to evaluate the scratch resistance of other materials, such as the Taber Abrasion test for plastics, textiles, and other materials.