List of blade materials

A variety of blade materials can be used to make the blade of a knife or other simple edged hand tool or weapon, such as a sickle, hatchet, or sword. The most common blade materials are carbon steel, stainless steel, tool steel, and alloy steel. Less common materials in blades include cobalt and titanium alloys, ceramic, obsidian, and plastic.

The hardness of steel is usually stated as a number on the Rockwell C scale (HRC). The Rockwell scale is a hardness scale based on the resistance to indentation a material has. This differs from other scales such as the Mohs scale (scratch resistance testing), which is used in mineralogy. As hardness increases, the blade becomes more capable of taking and holding an edge but is more difficult to sharpen and increasingly more brittle (commonly called less "tough"). Laminating harder steel between softer steel is an expensive process, though it gives the benefits of both "hard" and "soft" steels to some extent (see San mai and Damascus steel).