Reasons for punching holes in aluminium include making mounting brackets, creating venting in an enclosure and building your own passive solar heating system. The keys to how to punch holes in aluminium is the thickness of the aluminium you're trying to pierce. You'll use different tools for aluminium soda cans than for structural sheeting. Also, all holes don't have to be circular; with aluminium, it's possible to punch square or hexagonal holes to accommodate engineering specifications.
Determine the thickness of the aluminium you want to punch holes in. Depending on the thickness, you'll need specific tools for the punch.
Pierce the aluminium with a pair of scissors and cut out the size hole you need. If scissors are too big, use a punch tool to create a dimple hole. If the aluminium is too thick to cut with scissors or punch through with a punch tool, go to the next step.
Pierce the aluminium with metal shears and cut out the size hole you need. If this doesn't pierce the aluminium, try the next step.
Place the aluminium under a drill press and secure it in place. Make sure there's a metal cutting bit in the press. Slowly drill down and pierce the aluminium. A drill press with a metal bit will pierce any thickness of aluminium.
Pierce the aluminium by one of the methods mentioned above if the aluminium is thin enough to cut through with scissors or metal shears. If not, move to the next step.
Place the aluminium in a vice and cut it with a jigsaw. If the saw blade is unable to cut the aluminium, move to the next step using a drill press.
Place the aluminium under the drill press and drill consecutive circular sections along the inside of your intended shape. Punch out the shape with the help of the vice. Clean up any jagged edges with aluminium-grade buffing paper. It's like sandpaper but made specially to handle aluminium.
Always wear safety goggles when using a drill press or sanding aluminium.