How to rivet sheet metal?

Riveting different sheet metal parts together is common. The most common and simplest is pop riveting. It will not be waterproof, but you get a strong bandage.

With a hand tool, a rivet is pushed through pre-punched holes and deformed at the back. You can have recessed or bumpy heads on the rivet. If you must have flat surfaces on both sides, find other rivet methods.