Measure of a material's resistance to localized plastic deformation. Most hardness tests involve indentation, but hardness may be reported as resistance to scratching (file test), or rebound of a projectile bounced off the material (scleroscope hardness). Some common measures of indentation hardness are Brinell Hardness Number, Rockwell Hardness Number, ASTM Hardness Number, Diamond Pyramid Impact Test Hardness Number, Durometer Hardness, Knoop Hardness, and Pfund Hardness. A table relating various types of hardness values of metals is given in ASTM E-140. Hardness often is a good indication of tensile and wear properties of a material.