Why are "number 10 cans" called that?
All the good numbers were taken?
Pull up a chair for a short history of cans and their nomenclature and learn how out of date you really are.
When food cans were invented in the 1890s, there were no standards. Manufacturers produced cans to fit the products they sold. Within about ten years, however, food manufacturers realized that certain standard sizes were evolving and that there could be economic benefits to setting and following standards. And the standard can sizes that evolved came to be known by numbers from one to 10 (with a 2-1/2 thrown in for some reason).
These denominations were already falling out of favor by the 1920s. But in the past fifteen to twenty years, food companies realized that they didn't want to be in the business of producing their products and making cans. So almost without exception, they have gotten out of the packaging business and shifted that work to four companies that now dominate the global canning and bottling market.
Michael Dunleavy of Crown Holdings, Inc., the original developer of the bottle cap (the crown cork) and now one of the world's largest packaging companies, says nowadays, can manufacturers identify their products by two dimensions width across the top and height, both in inches. The old #4 can, which held peas, corn, and other vegetables, is now a 300 by 407 that is, 3 inches across the top by 4-7/16th inches tall. The old #5 can, which is a standard for large juice cans, is now a 404 by 700 4-4/16ths inches across the top by 7 inches tall. And an old #1, which is the size of most beverage cans, is a 211 by 400 2-11/16th-inches across by 4 inches tall.
In the canning world, then, there are no longer #10 cans. They exist only in the memories of restaurant and food-service workers. Next time you need one, tell the prep cook you need a "603 by 700 of peas" and see what you get….