In article
<7df748ee-fd2d-4e24-9e36-a92e27654180@m44g2000hsc.googlegroups.com>,
Dee Dee shentel.net> wrote:

As a machinist, I can speak with some level of so-called expertise on
this one. The Gauge of a metal is a measurement, and so cannot be
thinned and retain said gauge. The thickness of a given steel varies by
which form of steel is being measured. In the case of Stainless,
18-gauge measures .050, or "fifty thousandths," as a machinist or
metallurgist would say it.

Now this thickness is the thickness of the metal prior to pressing. The
punch press process will result in controlled distortions of the metal
and that will in turn lead to portions of the metal getting thinner, but
this is not in the way you were concerned with. The flat, top surface
of your table will retain its gauged thickness. It is edges, holes and
pressed forms that will result in stretching the material. These
extrusions will get thinner, but the forming will make these extrusions
in certain ways structurally stronger.

The concept of the thinning can be exhibited by taking a wide rubber
band and holding it between your hands barely taught. Looking at it, it
is straight and smooth. But as you pull it, the edges bow in towards
each other, making the band appear thinner.

Conversely, the form's shapes are used to make the overall metal
structurally stronger. Lay a piece of paper between to books of equal
thickenss and the paper cannot even support its own weight. But give
the paper a fan fold, bending the paper every half inch in opposing
directions until you have folded the piece of paper, and then lay it
back between the two books, and you will find it can hold several ounces
of weight. Likewise, the formed edges and ridges of your table add to
the table's strength. Folds can get a bit thicker, but any stretching
will cause the metal to get thinner.

Regardless the bending, forming and stretching, it is still considered
the same gauge of metal. As a matter of practical physics, it is not
possible to thin the metal by pushing it thinner. To thin sheet metal,
it must be rolled, similar to a pizza parlour's dough roller. Should
this be done, the metal then will have a thinner gauge, and cannot
legally be called the thicker gauge.

Hope this helps.

If you have any further questions, or I didn't explain anything here
quite clear, feel free to ask here or by e-mail.

jt