Numerical Control (NC) machining is a fabrication process used to cut parts such as screws, threads and other components using computer numerical control (CNC) equipment. The process is used to create custom parts from raw materials, such as stainless steel and aluminum alloy.
The advantage of using a CNC machine over manual machining is that it is more precise and accurate, and consistent with the design specifications. The CNC machining process starts by first creating a computer numerical control or CNC program, which is written in the CNC computer language. This program is the software code that will control the machining process.
The CNC program contains all the motion commands, such as speed and direction, as well as all of the machine functions, such as cutting direction, depth of cut, feed rate, and so forth. The program also contains the data required to produce a part, such as the number and shape of the machining path and the size and type of each tool used.
The CNC program is sent to the CNC machining center, which is controlled by a motor and a computer, and produces the part based on the programming commands. The machining process begins with a blank workpiece, which is then cut and shaped according to the programming commands. As the machine cycles through the program, the cutting tools are moved around the cutting area in a series of repeating patterns. The motion varies depending on the size, shape and cutting speed of the material being machined.
After a tool has been used to shape the part, the resulting shape is then reevaluated, and the program may need to go through another cycle to refine the shape. This cycle is known as finish machining. During this stage, tools with very accurate cutting edges are used to create a perfect finish.
Once the part is complete, a quality inspection is typically carried out to ensure that the part meets all of the quality standards and design requirements. The inspected part is then inspected visually, dimensionally and test-checked, and finally packaged for shipment to the customer.
CNC machining offers the advantages of precision, accuracy and high repeatability, which makes it well suited for creating extremely intricate and complex parts. The process is also highly efficient, requiring minimal operator input and producing parts in a relatively short amount of time. It is ideal for large-scale high-volume production or for creating one-off custom parts. Despite the investment in CNC equipment and the programming time needed to create the CNC programs, CNC machining is a cost-effective solution for many parts, such as threaded parts.
