CNC machining, which is also called precision machining, is a metal cutting or removal process by Computerized Numberical Control (CNC for short). It is aided by the CNC to reach a high and steady accuracy with less labor costs. Precision machining is any of various processes in which a piece of raw material (usually they are casting blanks, forged blanks or structural metal materials) is cut into a desired final shape and size by a controlled material-removal process. While the alloy steel CNC machining parts are the work pieces made of alloy steel (in forms of castings, forgings or alloy steel structures) by CNC machines.