What the best circular saw
- Adequate cutting power. A saw should be able to stand up to a hefty
piece of wood without bogging down. Professional framer Tim Uhler,
writing for the Journal of Light Construction, says a 15-amp in-line saw --
worm drive or hypoid -- is best equipped to stand up to the densest types of
lumber. In-line saws are typically geared to run at a lower speed than
sidewinder saws, so like a cyclist going uphill in a low gear, their lower
speed gives them more power on each push. However, most corded or cordless
sidewinder saws can still handle tough wood; they'll just take longer to get
- A snag-free blade guard. The blade guard is a crucial safety feature, but
it can also be a major annoyance if it gets stuck and stops the saw in mid-cut.
This is most likely to happen when you're cutting a compound angle or trimming
a small piece off the end of a board. Uhler says this
problem leads many professional contractors (who should know better) to pin
back the blade guards on their saws, or even remove them completely. Since a
safety feature can't protect you if it's disabled, it's crucial to choose a saw
with a blade guard that retracts smoothly at all blade depths and all angles.
Saws with a large protruding "lobe" at the leading edge of the blade
guard tend to work best.
- Other safety features. Aside from the blade guard, the most useful
safety feature for a saw is an electric blade brake, which stops the blade
quickly when the trigger is released. Without this feature, you have to wait
until the blade stops spinning before you can set down the saw. Other safety
features include a spindle lock, which keeps the blade from moving while you
switch blades, and a safety switch (sometimes called a "lockout switch")
to prevent accidental starts.
- A sturdy base plate. A saw's base plate, or shoe, is one of the most
commonly broken parts. Stainless steel base plates are the worst, as they can
bend easily if the saw is dropped. Cast aluminum or cast magnesium base plates
are better, but they can crack if dropped from a significant height.
Fiber-reinforced plastic shoes are the toughest, provided they're thick enough
to be stiff. In general, the best base plates are thick and heavily ribbed,
with square edges.
- A stable connection between base plate and blade. Every circular saw's motor and handle
assembly connects to the base plate at a pivot point, allowing you to adjust
the depth of the cut or the bevel angle. On saws that place this pivot point in line with the blade guard, pushing
down on the handle can tilt the motor, resulting in a bevel you didn't want.
Saws with the pivot point in line with the rear handle tend to be more stable.
- Smooth bevel adjustment. If you plan to do a lot of framing work,
particularly for roofs, a smooth bevel function is crucial. The bevel gauge
should be easy to read, with clearly engraved markings in one-degree increments
so you can dial in the exact angle you need. The base should also pivot
smoothly when you adjust it. It's convenient to have bevel stops, or detents,
at commonly used angles, such as 22.5 degrees and 45 degrees, but it should
also be easy to override these detents and set the bevel to even bigger angles
if you need to.
- Easy depth adjustment. To adjust the depth of your cut on a circular
saw, you need to loosen a lever and move the base plate up or down. This is
hard to do on a saw with inboard levers, which are tucked between the handle
and the blade guard. Outboard levers, located to the left of the handle, let
you keep one hand on the handle and use the other to adjust and lock the blade
depth. Levers are also easier to grasp when they're thick and rounded or coated
in rubber. The depth-setting bracket should slide smoothly without binding, and
the depth scale should be clearly marked – ideally with engraved numbers
rather than stickers that can wear off.
- Clear cut-line visibility. To make accurate cuts, you need a cut-line
marker that's perfectly aligned with the kerf (cutting edge) of your blade, for
both 90-degree and 45-degree cuts. The best indicators mark both sides of the
kerf, so you can cut either to the right or the left of the line. However, it's
not always possible to see your cut-line marker from all positions, so you also
have a window that provides a clear light of sight to the blade itself. On some
saws, handles or guards can obstruct this window at maximum cutting depth,
blocking your view of the blade.
- Useful extras.
Some saws come with additional features that, while not crucial, are handy to
have. For instance, experts particularly like saws with onboard storage for an
Allen wrench, so the tool is always ready to hand when you need to change the
blade. Another nice feature is an LED work light that illuminates your cutting
are, making it easier to follow your cut line even in dim light. And for
cordless circular saws, a battery fuel gauge is useful.
Know before you go
Check the weight and balance. Even the best-designed saw in the world won't
work for you if it feels uncomfortable in your hands. Experts recommend going
to a few different stores and trying out multiple saws, handling them just as
you would during actual use, to get a good sense of how they feel. Make sure to
test the saw in the positions you'll it in most often; the most comfortable
handles for overhead work may not be best for long cuts across plywood. Also,
if you work in a cold climate, you should also test the saw with gloves on to
make sure there's enough space around the trigger for them.
Blade-left or blade-right? Most corded sidewinder circular saws have the
blade mounted to the right of the motor, while cordless circular saws most
often put it on the left. Each arrangement has its pros and cons. For a
right-handed user, putting the blade on the right makes it harder to see, but
it also shields your face from sawdust as you cut. Having the blade on the left
gives you a clearer view but exposes you to more dust – and it also -puts
the weight of the saw on the "drop" side of the board, so you can't
use the board to help stabilize the saw when making short cuts. For a lefty, of
course, these advantages and disadvantages are reversed. It's up to you to
figure out which configuration is more convenient for you.
For cordless saws, consider battery life. Most of the cordless saws in this report use
lithium-ion batteries, rather than the heavier and faster-draining
nickel-cadmium (NiCd) type. However, some
manufacturers' batteries last longer than others, and some take longer to
recharge once they're drained. In general, the more powerful a cordless saw is,
the faster it will drain the battery. If you want your saw to go at least a few
hours between charges, choose a battery with a higher capacity – at least
3 ampere-hours (Ah), and preferably 4 or 5.
Choose your accessories. One accessory many reviewers consider especially
useful is a rafter hook, which lets you hang your saw from a joist, rafter, or
sawhorse, ready to grab the next time you need it. Users also express a strong
preference for larger carrying cases with storage for additional blades.
Finally, most users recommend adding a rip fence – a metal bar that runs
parallel to the blade to guide your cuts – if your saw doesn't come with
Value expectations: The
dollars and cents of it
the best saw is only as good as its blade – and the standard blades that
circular saws come equipped with vary widely in quality. The best manufacturers
don't necessarily provide the best blades, either; even excellent saws like the Makita 5007MG (Est. $150) get a fair number of complaints from users about
their low-quality blades. In several professional comparison tests of circular saws, the first
thing the testers generally do is to replace the factory blades on all the saws
with new, identical blades to level the playing field. The blade they
consistently choose is the Irwin Marathon blade (Est. $10),
which includes such high-quality features as carbide teeth and a smooth
silicone coating to slide through resinous materials. So if you're already
investing $100 or more in a circular saw, consider spending an extra $10 on one
of these blades to get the most out of your new tool.