Write an article based on this "Purchase a cold chisel that is 1 size wider than the aluminum. Sharpen your chisel Place your aluminum piece into your vice and tighten it. Align the chisel with your vice's screw and hammer the aluminum."
Use a measuring tape to determine the width of your aluminum. Afterwards, select an appropriate sized chisel. Common sizes are 1⁄4 inch (0.64 cm), 1⁄2 inch (1.3 cm), 3⁄4 inch (1.9 cm), and 1 inch (2.5 cm). For example, if your aluminum piece is 1⁄4 inch (0.64 cm) wide, use a chisel that is 1⁄2 inch (1.3 cm) wide. to a 60- to 70-degree bevel using a honing guide. Fit your chisel into your honing guide (a tool that clamps onto your tool either from the sides or from above and below) and tighten the screws on both sides to keep it in place. Set the guide to the appropriate angle, and then place the bevel (the metal edge of your chisel) against a second-cut, medium-coarse file. Hold the guide with both hands and move the chisel back and forth in a thin, figure-eight pattern. Once you notice scratches on your chisel's bevel, switch to a medium grit. When new scratches begin to appear, switch to a fine grit. Wipe the bevel between each grit using a dry, clean cloth. Position the piece in the center of the vice's jaws. Make sure that it's tightened firmly in place. Be sure to use a heavy-duty model bench vice. Hold the chisel tip against the metal—perpendicular to it—with your non-dominant hand. Use a ball-peen hammer to strike the chisel's handle and always cut perpendicular to the jaws of the vice. Continue striking the metal until there is a notch in it. At this point, you should easily be able to snap it into 2 pieces with your hands.  You should be able to cut your aluminum metal piece within 30 seconds. Anything longer and you're probably using the wrong sized chisel, or you need to use a saw.  Add 1 drop of 30-weight machine oil to the chisel's edge for lubrication. This makes it easier for your chisel to get into your aluminum's hardened grains of metal. Never use a claw hammer—the heads are not designed for hitting hard metal and are prone to chipping. If you're cutting a line in a sheet of aluminum, you can skip the vice and cut your way down the sheet on a flat surface. Use wood as a backing piece to help push the chisel through the metal and prevent the chisel's tip from wearing.