Machining is a manufacturing process that produces products, parts and designs by removing layers from workpieces. There are several types of machining, including the use of a set of power-driven machining tools to cut, and grind workpieces to meet specific requirements. Metal fasteners, artificial jewelry, toys, and hand tools are all machined into shape. Sometimes finished parts need to be retouched to meet quality standards or manufacturing requirements. In these cases, it may need to be machined to give it the proper appearance.
Although machining is used for the forming of metals, it can also be used for other materials. Molding is a common method of producing plastic and rubber products. In some cases, after molding, additional properties may need to be added. This is usually done by machining, which can add holes, deburr, or finish shaping. Although the material is soft and elastic like paper, it can still be processed into special designs or forms.
Tools used in Machining
A wide variety of machining tools are used to shape and die cast metals to produce specific geometries. Part of the machining process is the use of clamping devices to hold the workpiece as the tool runs through. Before the Industrial Revolution, machining was done by hand. Modern technology utilizes Computer Numerical Controls (CNC) to program these manual processes with precision and repetition many times in machining equipment.
Sometimes several different tools are needed to perform the various operations required to shape a workpiece. The types of tools selected are carefully selected to ensure the quality of the final product.
Several machining tools are listed and described below:
Drills use a drill to cut a circular cross-section hole in the workpiece to remove this portion of material. It is the most common machining process with a usage rate of about 75%. The jig is placed into a chuck attached to the spindle, which is driven by a pulley and a motor-driven drill. Lower the drilling tool to the workpiece surface either electrically or manually.
Three-dimensional shapes are milled using a rotating multi-blade tool. In CNC machining, milling cutters can be programmed to move in multiple directions on a fixed workpiece. The process can create parts with various shapes such as slots, pockets and grooves. Depending on the type of cutting required, there are different milling cutters to choose from.
A grinding or abrasive working machine is a cutting tool used to perform several different operations. Different types of grinding tools include surface, cylindrical, centerless, internal and specially designed. Surface grinders create flat, angular and irregular surfaces, while cylindrical grinders complete the outer surface of the cylinder. Centerless grinding feeds the workpiece into the insert. Internal grinding to complete tapered or straight holes. Over the past decade, grinding has been increasingly used in manufacturing and has become a manufacturing standard.
In turning tool operations, the workpiece rotates as the tool removes the coating from the workpiece. The process is similar to boring, but the outer surface of the workpiece is reconfigured instead of the center section. A typical turning tool is the lathe, an ancient craft dating back to Egyptian times.
A cutting tool is a wedge-sharp tool used to remove coatings from workpieces by shearing. It can use a single-point or multi-point tool, which must be harder than the workpiece. These precision tools are designed to withstand the heat generated during cutting.