Is there a definition for "heavy gauge" sheet steel? In other words, does a sheet need to be greater than some minimum thickness to be called heavy gauge? Or, as I now suspect, is this more of a subjective term?
The AISI "Steel Products Manuals" (which may be out of print by now) may shed some light on this. I will look around and see if we have those here. But, I vaguely recall that anything over 12 gauge was considered "heavy" and anything over 1/4" was considered plate.
I did locate the AISI books and there is a designation "Heavy Thickness" for coiled hot rolled sheet that applies to thicknesses over .180", which would be 7 gauge.
I've always taken "heavy gage" in a catalog listing or similar usage to just mean thicker than usual or plenty thick. A "heavy gauge" beer can wouldn't have to be very thick.