As I recall, a framing saw is calibrated square and a center punch is
used to dent at the inside or outside of the V pint between the arms.

At the inside it spreads. Outside it pinches.

Martin

-MIKE- wrote:
On 3/14/10 5:21 PM, HeyBub wrote:
Good points. I recall, however, from teaching Physics labs, that one
should
avoid using the end of a ruler -such as a yard stick (actually, we used
"meter" sticks) - as a starting point. Start at the 1" mark and
subtract one
inch from the result to get the true distance. The reason is that the
ends
of measuring devices get boogered up and distort the beginning point.


Yeah, I think we all have learned to start at the one, at some point in
our experience.
But since the topic is "precision" framing square. I know that's an
oxymoron. -)

In any case, I like to have at least one nice L square and one nice rule
(from a combination square) that are each sanded "true zero" on each end
and at the corners.

I often find myself with a square and a file, taking of the blister from
a ding at the corner where it's been dropped on the concrete floor.