Hardner

Hardness is a measure of how much a material resists changes in shape. Hard things resist pressure. Some examples of hard materials are diamond, boron carbide, quartz, tempered steel, ice, granite, concrete. Ability of material to resist wear, tear, scratching, abrasion cutting is called hardness.Metal hardness is a characteristic that determines the surface wear and abrasive resistance. The ability of a material to resist denting from impact is related to hardness as well as a material's ductility.