Chris Friesen wrote:
I saw the following in an ad for Excalibur:

"...we won't use stainless steel for guide rails for example. It is
just not reliably straight enough for our standards..."

Why would stainless be any less straight than any other kind of steel?

Stainless has both a higher strength than mild steel, and it work
hardens much more rapidly as it is formed. Rectangular tubes in
stainless will end up with higher residual stresses after forming and
welding than tubes from mild steel. These stresses will tend to
distort the tube from a perfect shape. I expect the tube mills
guarantee better straightness on mild steel tubing.

All that said, however, this claim is primarily marketing hype.
Exactor sells sliding tables that are (or at least started as) copies
of Excalibur's. Exactor tried to differentiate theirs by using
stainless rails and claiming since there's no paint for the table
rollers to wear off, their sliding table stays more accurate over time.
Excalibur shot back that their painted steel rails are more accurate
to start with.

I see that Exactor now sells Biesemeyer-clone rip fences. The front
rail they use is painted mild steel tubing. So if paint wearing off
was a big deal for accuracy, you'd wonder why they didn't use a
stainless rail on their rip fence, too?

Anyway, I've got the Excalibur sliding table and Exactor overarm blade
guard, both bought at woodworking shows for good discounts from list.
I'm very happy with both. When I got the sliding table, I talked to
both vendors at the same show. I wanted the 40" model to cut 4x8'
panels and the Exactor vendor insisted on selling me his 26" model
(which I think he had too many of). The Excalibur guy sold me the 40"
table for the price of the 26" Exactor. I didn't see any significant
mechanical differences between the two. If the prices were reversed, I
would have bought the Exactor. But now I've got one, I can't see
myself ever giving it up.

During hobby use for three years I don't see any evidence the paint is
wearing off the rails, but if it does, I doubt I would even be able to
measure the difference with a micrometer. I doubt if I could measure
the lack of straightness of stainless rails, either.

Tim