AS-9 Adjustable Square

Accuracy is undeniably the most important aspect of a try
square. Perfect ninety degrees exists only in mathematics. Once theory
meets the shop floor, things begin to degrade into the world of
variables. "Tolerance" is a fancy word meaning "this may not be exactly
what you think or need." Generally speaking, the accuracy of a try
square should be sufficient enough to allow you to make gap free joints
in hardwood. And, it's always easier to make drawers for a carcass if
it is square. Most European squares, and most American versions, are
manufactured to the "European standard" which is an angle variation of
0.001" for every lineal inch of blade length. This means a square with
a ten inch blade could be 0.010" out of square at the end of the blade:
either acute or obtuse. This is sufficient error for you to need filler
in your joints, and is simply unacceptable for quality work.

Never again will you have to worry about the accuracy of your squares because the  AS-9 feature our proprietary blade
adjustment mechanism. The existing paradigm of try square design and
manufacture has been changed forever.

The AS-9 Adjustable Try Squares are
factory calibrated to be within 0.001" of square, measured from the end
of the blade. That's one thousandth of an inch over the length of the
blade, inside and out! The most demanding craftspeople will revel in
the soothing comfort this accuracy provides. I am speaking from
experience when I share with you that woodworking takes on a new
dimension once you have tools you can implicitly trust. 

Accuracy not withstanding, both of these tools feature two
additional functions that are unique in the marketplace. Each has a
graduated blade, etched to government accuracy standards, and are
precisely registered in the handle. This allows you to use the inside
rule for extremely accurate measurements of length, and the outside
rule as a height gage. Accuracy of measurement is within 0.0025", which
is one half the thickness of a graduation mark on the rule. You will
not find a more useful or accurate square, anywhere, at any price.