For thin sheets of metal you can use tin snips to cut through it.
Cut through thin aluminum sheet.
Using a softer piece of material such as wood as a backer will allow the chisel to push through the metal and prevent wear on the chisel s tip.
Select a fine toothed blade and don t cut aluminum with a wall thickness of more than 1 4 inch 0 64 cm.
Cutting thin aluminum should require no more than a few basic tools and is therefore a task that can be easily tackled either on the spot or from any reasonably well equipped garage.
Then grip the saw with both hands and push the blade through the metal to cut it.
Start by taping both sides of the sheet metal directly over the line you want to cut and clamp the metal to a work station so it doesn t move.
If you use metal shears to cut thin sheet metal such as duct metal it curls and can be difficult to flaten properly.
Tired of getting fingers cut on sheet metal while using tin snips.
These photo steps show that it can be done using a utility knife.
Use a wood cutting saw with carbide tipped blades to cut most aluminum.
How to cut thin sheet metal and keep it flat.
The illustrations are for a small bracket but i have cut 3 foot.
Check out this video.