There’s not much we could o in the woodshop if we couldn’t make sure things were square. The most
popular tool to do that is a combination
square, a tool that looks much the same
as it did when Laroy S. Starret invented
it in 1879. But a new version from Kapro
gives that revered tool an upgrade.
The classic combination square
has an engraved metal rule, usually 12
inches, with a groove down the center
of one side. A machined cast head
slides on the rule with a spring-loaded
locking knob that uses the groove in
the rule to lock the head tight and
accurately at 90 degrees to the rule.
You can get other heads, but the classic
version has a 45-degree angle and a
90-degree angle plus a bubble level
and some kind of scribing instrument
inserted into the bottom of the head.
A different take
The classic tool has worked great for
140 years, so why change it? Kapro’s idea
is to make the tool even more versatile
and easy to use, and the secret to that
is magnets. The old locking method
was sometimes problematic. With use,
dirt would get in the groove, the spring
would get tired, the locking knob would
get hard to turn, and adjusting the head
on the rule would become a pain.
Kapro’s version (officially the model
325M) uses powerful magnets to lock
the rule in place. That makes it really
easy to slide the rule where you want
it, but the magnets are strong enough
to hold securely for measuring. Mak-
ing depth measurements by sliding the
head on the rule is sure and smooth.
You can instantly remove the rule to
use separately or to clean to ensure accuracy. And if you accidentally drop the
tool, it’s less likely to be damaged since
the rule will just be knocked loose.
More than magnets
The rule itself is nicely engraved for
easy reading with scales in 16ths and
32nds of an inch as well as millimeters
Combination square with a difference
and has precision milled sides. Rather
than inserting into a hole at the base,
the scribe rides in a recess held in by
the same magnets that hold the rule in
place. While old-style scribes frequently
fell out and were lost, there seems to be
less of a chance of that happening with
this system. The standard bubble level
is easy to read and highly visible.
At less than $25 and available at
major home centers and online outlets,
the Kapro magnetic lock combination
square is a real value and worth check-
ing out. For more information visit
by William Sampson
firstname.lastname@example.org IN THE SHOP
Common measuring device gets an upgrade from Kapro.
; Want more?
To see this in action,
watch our video on your
smart phone or online
William Sampson is a lifelong
woodworker and the editor of FDMC
The Kapro magnetic combination square uses powerful magnets to hold the rule in
place, making measurements and adjustments much easier.