ABSTRACT
The first step in selecting an appropriate material is to develop a functional specification of the device that quantifies the operating environment and life expectancy. This specification can then be evaluated against material costs and the necessary processing requirements. In many designs, there are some material properties that are absolutely essential and others that may be somewhat subjective and likely to be selected based on cost and market considerations. For example, a shovel is typically a twopiece device that has a metal end attached to a handle. The metal end must be durable and somewhat corrosion-resistant; selecting a material in this case is fairly straightforward. The handle can be made from numerous materials because there are many that meet the necessary functional requirements, causing the material selection to be driven by marketing requirements rather than engineering necessities. Materials most often selected for this application include wood and composites which differ significantly in raw material and fabrication costs. Since either of these offer a solution to the design problem, the selection becomes based on the desired market and selling price.
