Give me matter, and I will construct a world out of it. Immanuel Kant

Material and manufacturing process selection are essential for design. Being able to exploit a material’s potential and characteristics is necessary to ensure that the best material is used for a particular machine element. This chapter will classify, characterize, and guide selection of solid materials in a general sense. Physical and mechanical properties of engineering materials will be examined and two-parameter charts will be used to suggest materials for specific situations. The hardness of materials will be defined, hardness testing will be described, and the importance of hardness will be discussed. A brief summary of the manufacturing processes that are available for each material class will be discussed, with an introduction to their relationship to mechanical design. Processes can be categorized as casting, where a metal is melted, placed in a mold, and cooled to solidification; bulk forming, where a material is forced to take on a new shape; sheet forming, which uses a rolled metal with small thickness to produce a desired shape; material removal processes such as machining, grinding, and other finishing processes; various methods to produce polymer parts; and methods to produce ceramics and composite materials.