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Old May 2, 2007   #15
ZBQ's Avatar
Join Date: Mar 2006
Location: Southern Ohio
Posts: 170

Ok, here is a question for the scientists like dcarch.

I was just looking at pressure canners over at Amazon and there are only a couple of stainless models with the rest being aluminum. Some stamped, some cast.

The question. Will a good heavy CAST aluminum pressure canner bulge out on the bottom like a lower priced STAMPED model?

For those who don't understand the difference bettween "cast" and "stamped". They are different manufacturing processes.

Stamped is where a flat sheet of metal is fed into a press (many tons of pressure) and the sheet is "stamped/pressed" into the shape of the final product. This may take several stages to get to final product shape.

Cast is where molten aluminum is poured into a mold in the general shape of the final product. This process results in much stronger end product because it can be made to what ever thickness necessary.

Stamping thickness is restricted in a couple of ways. First, the capacity (tonnage) of the press to shape the metal and second by the mallability of the metal, that is, how well and to what extent it can be shaped under pressure without fracturing or losing its temper. Generally, stamped products have to be made of a "softer" alloy and thinner thickness to allow the metal to be shaped and bent without fracturing. Where as cast products can be made of a "harder" (or more brittle for lack of a better term) alloy since they are not going to be bent or shaped. Cast products are generally machined on a lathe or mill and result in a higher quality, stronger product.

This is exactly why forged culinary knives are of a better quality than stamped blades.

OOPS....sorry for the metallurgy disertation!!

What do you think dcarch? Aren't you an engineer? Or am I thinking of the wrong person?
"To wander this country and this world looking for the best barbecue — and
never actually finding it would be a life well spent, a delicious journey in which
enlightenment comes with the search — not the arrival." - Anthony Bourdain
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