I had forgotten about these till a question on another forum about spillage when pouring from the useless rectangular cans quart and gallon, I also had some made out of the square 5 gallon cans but none of those left. I have since switched to the plastic shoe boxes and lidded plastic storage boxes.
Here is the side and end view, I leave about ½" of extra metal To fold over for stiffener.
Here are the quart cans, same deal only used 3/8" fold over
To answer the questions he had the shape is due to shipping and shelf space.
May not help with the slop in pouring, but it does make one feel better in turning scrap into something useful.
I have used a 2"dia funnel Aluminum with a short length large dia spout to keep the spillage down. I believe it is a canning funnel.
