If it’s not possible to alter blade sizes, consider purchasing equipment with a variable speed router and use the slowest setting. These types of equipment are typically more expensive, but offer a degree of flexibility ideal for cutting aluminum.

As an additional safety measure, use a push stick to hold and move your aluminum piece into the saw. This allows you to cut your aluminum without getting near the blades. Since aluminum does not tend to close as you cut it, create narrow kerfs whenever you can.

WD-40 is the standard lubricant when cutting aluminum. Apply 5 to 6 small spurts on both the bottom and top halves of the blade.

Remain clear from the kickback zone (where recently cut pieces are thrown clear by the power of the saw) when cutting. This is usually directly behind the saw. Alternately, you can use a bridge to secure your saw and reduce kickback. Always keep your fingers away from the saw blade.

Always keep the power off when adjusting blade depth.

Keep your blade aligned with the cut line. Always use carbide-tipped blades. Lubricate the blade before using it, and cut slowly.

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.

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.

Be sure to use a heavy-duty model bench vice.

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. [8] X Research source 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. [9] X Research source

Avoid straight-cutting snips—even if you manage to cut a circle, the hole will end up having a jagged edge. Use both green and red snips for tough cuts. When 1 pair stops working, swap snips. Air conditioning and heating work will most likely require you to alternate between the two because they require a combination of straight and curved cuts.

The longer your straight cut, the longer your strokes should be. Compound snips are designed for situations that require maneuvering as opposed to straight cuts. If you have no other option, be sure to fully open and close the snips for each stroke that you make—this will ensure maximum cut length.

Straight-cutting compound strips are most effective for doubled-up or thick sheet metal. They can typically handle a maximum of 18-gauge mild steel, which is equivalent to 0. 0403 inch (0. 102 cm) thick aluminum. [13] X Research source Avoid using straight-cutting compound strips for cutting curves.