What is CNC Punching?
Design considerations when CNC punching sheet metal fabrications
CNC punching is a manufacturing process that is carried out by CNC punch presses on sheet metal materials. These machines can be either a single head and tool rail (Trumpf) design or multi-tool turret design. The machine is basically programmed to move a sheet of metal in an x and y direction so as to accurately position the sheet under the machine’s ram ready to punch a hole. The processing range for most CNC punch presses is 0.5mm to 6.0mm thick in a range of sheet metal materials including steel, stainless steel and aluminium. The choice of hole punched can be as simple as a circle or rectangle through to special shapes to suit a specific sheet metal design. By using a combination of single hits and overlapping geometries, complex can be produced. The machine may also punch 3D forms such as dimples, taptite screw thread plunges, electrical knockouts and earth tags which are often employed in sheet metal enclosure designs. Some modern sheet metal punch press machines may have the ability to tap threads, fold small tabs, punch sheared edges without any tool witness marks making the machine very productive within the component cycle time. The instruction to drive the machine to create the desired component geometry is known as the CNC program.
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