Freely-programmable hole patterns with varying diameters are to be punched into stainless steel and coated aluminium tubes. The corresponding hole patterns are entered by the operator in a plain text display. The tube lengths can also be freely selected within a range of 250 mm to 2000 mm. Once the operator has inserted the workpiece, the punching process takes place automatically. Due to the use of special materials no markings are left on the tube after punching.