Things You'll Need
Instructions
Cut the 4-inch-by-4-inch boards to the length of your sheet metal. Secure the lumber between two vises on a well-anchored work table.
Mark the bend line on the metal and slide it between the lumber with the bend line slightly above the lumber.
Lay the 2-inch-by-4-inch board against the metal, just above the bend line, and hammer against the wood until the metal bends. Continue along the length of the metal until it is bent.