CNC machining is a method of subtractive manufacturing that uses programming codes to control and guide the machine tool to cut (subtract) material until the designed part is finally formed. CNC machining and manufacturing processes use a wide range of materials, including metals (iron, stainless steel, aluminum, copper, or metal alloys), plastics (PEEK, PTFE, nylon), wood, and composite materials. Its best material depends on the product’s specifications and application, and the material has sufficient hardness, tensile strength, shear strength, chemical resistance and temperature resistance to withstand the processing process. The physical properties of the workpiece determine the optimal cutting speed, feed rate and depth.