Billet refers to a cast semi finished product. It is also referred to as ingot, particularly for smaller sizes. A billet is typically cast to a rectangular, hexagonal or round cross section compatible with secondary processing, e.g. forging. It can be produced either as coil or cut lengths. Ingots and billets are collectively known as barstock.
References
Schey, J. A., Introduction to Manufacturing Processes, McGraw-Hill (1999).
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