The cost of an aluminum can isn't just the costs of the metal to make it. It's the cost of the machines to make it into a can which requires metal which will cost more. It's cost of the trucks that deliver it there made out of metal. Many other costs will be added to that pop can. Trumpets claim that it will cost only 3 cents more a can is fake news. It doesn't take into account all the costs of making that can.
Tariffs will cost consumers more then Trump and his cronies will tell you. Plus if other countries follow suit the costs will magnify greatly. In the end the American people will lose money , jobs , and much more.