"Richard" wrote in message
oups.com...
I've noticed that a folding carpenter's rule is often included in lists
of essential basic tools. I'm not sure I understand how a folding ruler
differs from a tape measurer. Could anyone explain what the advantage
of a folding ruler is?

Thanks,
Richard



Metal tapes expand and contract with temperature at a different rate
than wood. If you want to be real accurate, a wood carpenter's rule
would expand and contract nearly the same as your wood would.
(However, I'd be the first to admit that, over the usual 6' or so,
the difference wouldn't be much to speak of.)
Over long distances, steel tapes stretch a little, too. Between temp and
tension, the difference can be 1/4" or so. Some longer tapes are made
of fiberglass, and probably are best used with a "calibrated" tension, too.

But mostly, I find that a rule with the extender eliminates the
guesstimating
required when doing inside measurements -- no trying to "read the curve."

"Chip"