Here’s why some tins are smooth and others have ridges:

  • 1.) Ribbing on Tin Cans strengthens the tin.

You can see the general principle in cardboard. The centre is corrugated because a little paper can add a lot of strength that way. The can is curved and the ridges reduce your ability to dent the can with normal handling. Compare to a typical aluminium soda can that has thinner walls and no corrugation of the metal. It’s pretty easy to dent empty soda cans with hand pressure. The area of the food can with the ridges will be quite hard to dent with hand pressure.

  • 2.) Furthermore, the ridges on tins allow it to expand and contract.

As part of the canning process, filled cans are often heated to cook and sterilise the contents. This can build up a fair amount of pressure, and the ridges let the can handle that without splitting.

  • 3.) Not all tin cans require ribbing.

The sides of the can are ribbed to increase the strength of the can and provide protection against the high temperatures and vacuum pressures of thermal processing and boiling preservation during the canning process. Certain products such as coffee do not require the cans to undergo such procedures and thus you will often find coffee cans with no ribbing at all.