It is a value-added[1] process involving the creation of machines, parts, and structures from various raw materials.
Typically, a fabrication shop bids on a job, usually based on engineering drawings, and if awarded the contract, builds the product.
Large fab shops employ a multitude of value-added processes, including welding, cutting, forming and machining.
The end products of other common types of metalworking, such as machining, metal stamping, forging, and casting, may be similar in shape and function, but those processes are not classified as fabrication.
Burn tables are CNC (computer-operated) cutting torches, usually powered by natural gas.
Forming converts flat sheet metal into 3-D parts[4] by applying force without adding or removing material.
[6] Most metallic materials, being at least somewhat ductile and capable of considerable permanent deformation without cracking or breaking, lend themselves particularly well to these techniques.
Machining is a specialized trade of removing material from a block of metal to make it a desired shape.