Disk cutters are used to punch out disks from a sheet of metal. Circular disk cutters are the most common, though a range of shapes are available. A disk cutter consists of two steel die plates, either separate, permanently attached with a calibrated space between them, or connected with a lever to raise and lower the top plate as needed. They have a variety of precisely machined die holes/channels with matching punches. The cutting end of the punches are smooth, slightly angled, and have a flat surface; the striking end is usually slightly beveled. Before you begin, determine the manufacturer’s recommendation for gauge tolerances and acceptable metal types. Don’t cut thicker metal than recommended or you will damage your tool.
Position the die plates on a flat piece of wood. Select the size of the disk you’d like to cut, and slide your metal between the two die plates. To conserve metal, begin at the corner of a sheet. Look into the die channel and adjust the metal to make sure you have enough clearance to cut a complete disk.
Select the correct-size punch for the hole/channel you’ve selected, lubricate it, and place it cutting-side down into the hole/channel. Use a brass mallet to strike the punch (shown above). Try and use one decisive blow to cut through the metal rather than multiple small hits. A single blow results in a cleaner cut; multiple hits may result in a ridged or doubled edge.
Lift the die plates slightly off your wooden work surface, and the cut metal disk and punch will fall out. If the punch is stuck, there are a couple ways you can remove it. Hold the die plates approximately ¼ in. (6.5 mm) above your work surface, and lightly tap the punch to release it. Or, turn the die plates over, and set them at an angle on your bench. Insert a wooden chopstick or dowel into the channel against the cutting end of the punch, and use a mallet to strike the chopstick or dowel and remove the punch. Don’t let the punch fall onto a hard surface, or the cutting edge may be damaged.