6.4 Material Selection
Tim A. Bacon
Unless it is an in-house job where the machinist has a choice of materials, material selection is mandated by the customer. In the aerospace industry, customers require specific material for their parts. The certifications that accompany the material establishes that the material being used is appropriate for the job. The type of material required for a part is typically called out on the technical drawing. Common types of material are aluminum 6061, mild steel 1018, cold rolled steel 12L14, or acetal.
Aluminum 6061 is a strong, lightweight material that can be used in structural applications.
Mild steel 1018 is good for fastener parts and can be case hardened.
Cold drawn 12L14 is a free machining material. This means it is easily machined. It is good for parts that require a considerable amount of machining.
Acetal is commonly used as an alternative to metals. Mechanical gears, electrical components, and medical products are examples of its applications.
Typically, the material callout will be in the title block of the drawing. For our bench block project, we will use 1018 mild steel or something similar.