Q&A -- Understanding Stovetop Cookware

[Dave the Cook]

Sorry, I should have added earlier: the reason I included the second photo even though it's less clear in most aspects, is because it shows the correct proportion of steel to aluminum to copper (pretty close to 1:2:4). If you look at the upper edge in the second photo, you'll see the steel is thinner than the aluminum.

Also, although I had no way to measure it, the upper and lower layers appeared to be mirror images of each other.

Just for fun, here's an All-Clad S/S edge (one of the two pieces of A-C that I own, neither of which I paid for:

[jeremyn]

Hey Dave,

Are you able to measure the total thickness of those All-Clad Stainless pieces? The article says that the Stainless pieces have about 2mm of aluminum, so if this method indicates that, then we can assume it is pretty accurate.

[jeremyn]

Just thought I'd give an update. In researching various cookware lines, I got the specs of the Scanpan Fusion 5 and Fusion CS5 pieces (directly from Scanpan).

The Fusion 5 line is fully clad aluminum with an inner layer of 0.8mm 18/10 stainless, a middle layer of 1.4 mm aluminum & aluminum alloys, and an outer layer of 0.8mm 18/0 magnetic stainless.

The Fusion CS5 line has an inner layer of 0.8mm 18/10 stainless, a middle layer of 1.4 mm aluminum & aluminum alloys, and an outer layer of 0.8mm copper.

[jeremyn]

I seem to have found the patent under which All Clad describes its copper core production.

Copper Core Patent

It seems to indicate a total thickness of 1.83mm with a copper core of 0.91 mm, total aluminum thickness of 0.2mm, and stainless thickness of 0.71 mm. Assuming this is the actual process they use, it looks like our guesses were about right (at least for the copper layer).

[tim]

It seems to indicate a total thickness of 1.83mm with a copper core of 0.91 mm, total aluminum thickness of 0.2mm, and stainless thickness of 0.71 mm.  Assuming this is the actual process they use, it looks like our guesses were about right (at least for the copper layer).

←

Hi,

Your thickness references are prior to roll bonding.

The patent states, "After roll bonding with the outer layers 8 of stainless steel, the 5-ply composite 10 of the present invention, in a presently preferred embodiment, has an overall thickness of about 0.072 inch which is particularly suitable for the manufacture of various sizes of cookware. By way of example, such a 5-ply composite 10 of 0.072 inch in thickness would have a copper core 2 of 0.036 inch in

thickness, having pure aluminum layers 4 having a thickness of 0.004 inch

each, and outer layers 8 of stainless steel of 0.014 inch in thickness."

The picture seem to show the aluminum layers as much thicker than the stainless linings. Interesting.

Tim

[jeremyn]

The figures I quoted were actually the same ones as yours, after roll bonding, but converted to millimeters. 0.036" of copper = .91 mm, etc.

Yeah, it is interesting that the picture shows the aluminum much thicker...it's possible that this isn't the exact process that they use.

[tim]

Yeah, it is interesting that the picture shows the aluminum much thicker...it's possible that this isn't the exact process that they use.

←

Hi,

It is possible that the dramatic increase in the price of stainless steel may have lead to a decision to use thicker aluminum layers and thinner linings.

Tim

[slkinsey]

I think the picture is limiting because of low resolution and distortion. I blew up the layers from the left hand side of Dave's top picture, because it seemed the least distorted and the most focused view of the layers. This is what I got:

Even with this image, the layers at the top are more discernable than the layers on the bottom. What I got was the following:

Stainless: 17.5%

Aluminum: 8%

Copper: 49%

Aluminum 8%

Stainless: 17.5%

If we apply these measurements to the patent and the stated layer thicknesses at 0.072 inches, we get the following:

Stainless: 0.014 inches (patent) versus 0.0126 inches (photo) -- difference is 0.0014 inches.

Aluminum: 0.004 inches (patent) versus .00576 inches (photo) -- difference is 0.00176 inches.

Copper: 0.036 inches (patent) versus 0.03528 inches (photo) -- difference is 0.00072 inches.

This means that the photo accords with the patent information to a very high degree of precision. A higher resolution and more in-focus photograph (no disrespect to Dave, who wasn't exactly doing this with a tripod and studio lighting!) would undoubtedly have resulted in an even greater degree of correspondence.

[sygyzy]

Since it doesn't seem like Calphalon Commercial exists anymore (now called One?), is the One still a good deal? What is a good brand/model to look at for 8, 10, 12 inch non-stick fry pans? Also, is an omlette fry pan the same thing as a fry pan?

Thanks.

 

[Moderator note: The original Q&A - Understanding Stovetop Cookware topic became too large for our servers to handle efficiently, so we've divided it up; the following part of this discussion is here: Q&A - Understanding Stovetop Cookware (2009-)]