Dating Presto Pressure Canners

It finally makes sense.

For years, I’ve been speculating about exactly what the numbers on the rim of Presto’s cast-aluminum pressure canners actually mean. I now have what I believe to be confirmation.

On the rim of the Presto-made cast-aluminum canners there’s a series of three two-digit numbers as show here:

Or here:

I was sure that these markings meant something – Presto wouldn’t have gone through the trouble otherwise, right?

The first set of markings always made complete sense. The 21-B is a 21 quart canner, and my Sears is a 16 quart. Having the canner bottoms labeled as such made perfect sense.

The last number being a year also made sense to me, but I figured could have been open to some interpretation. There are references out there on parts websites, for example, that refer to parts for the cast-aluminum canners as “made in 1971 or before”. I always thought that my 21-B pictured above would have been one of the last cast-aluminum canners Presto made. I did wonder if I was correct or not.

I didn’t have any idea what the middle number could be. Several years ago I had asked in an online canning group and they suggested it could be a week of manufacture. While this made some sense to me, I had a 1967 canner bottom that had a middle number of 51. I wondered if the factory was working right up until Christmas that year. I now think they were.

In 2018, I walked into a local Goodwill and found a Sears-badged cast-aluminum Presto canner. It was in great shape, had what I have no reason to doubt was the original manual, and I didn’t need ANOTHER canner, so I brought it home anyway. I scanned in the manual, did a blog post about it, and went on with my life.

Enter 2021.

I ran across the paper manual and picked it up, asking myself, “did I ever scan this one?” While I was paging through it I noticed this gem:

This canner has “16 14 69” on its rim. It’s a 16 quart. The manual has a copyright date of 1968. This handwritten note would likely be the date the previous owner bought it – 6-15-69.

If the “14” really is the week of manufacture, that would mean that the foundry cast this particular canner after the Easter weekend in 1968. I think it not only likely, but entirely plausible that a canner produced just after Easter in 1969 could have made it into someones hands by canning season in June.

Mystery solved.