This is the question
that seems to come up with anyone who isn’t the most advanced of
users. In carbide circular saw blades, there are so many options, so
many designs and configurations it’s overwhelming to some,
especially those who never knew there were any choices.
I’m going to try to clarify and simplify the selection process for
you here. But first, I want to talk a little about the saw itself,
since choosing the wrong saw can create real headaches when it comes
to trying to buy replacement and specialty blades. Keep in mind not
only the size of the saw, but the size of the arbor when selecting a
new power saw. Or picking up an old one at a yard sale, estate sale,
etc. There are some great old table saws out there, like the old,
solid-as-a-rock Sears models that have 3/4" arbor shafts, for
example. Then there was the huge batch of Asian-made 10” miter
saws on eBay with 1” arbors. With cheap OEM blades on them. When I
saw those, I knew in a few months I’d be getting emails from folks
looking for new blades for the bargain saws they bought – blades
no one makes. I was right. And those bargain shoppers found out
it’s almost impossible to get blades off the shelf, that if
they’re lucky, they can get one bored to fit – at a price.
Almost all power saws for the American retail market from about 8”
to 10” come standard with a 5/8” arbor so that’s what blades
are made for. Anything 12” and larger comes with a 1” arbor.
DeWalt makes some 12” miter saws that come with a reducer so you
can use either arbor size and there are some 12” industrial double
miters that (like Pistorius) that have a 5/8” shaft. But other
than those, the standard arbor sizes are about written in stone so
if you’re shopping for a new saw, stick with them.
Okay, now about those blades……
Size (or Diameter)
This one may seem pretty obvious but once in a while I run across
someone who wants to use a blade that’s a different size than
their saw (sometimes to save money, believe it or not). In most
cases, I advise against it. First of all, there’s the issue of
clearance: a bigger blade won’t likely clear the blade guard on a
miter or radial arm or the throat plate on a table saw. A smaller
blade won’t give you the depth of cut.
Then there’s what’s not so plain to see: the design and geometry
of the blade. Smaller saws run at higher RPM, the bigger the saw,
the lower the RPM. Blades are designed to work in concert with the
saw to give you optimal performance. Enough said about that.
Exceptions? Yes, most notably a dado. Most craftsmen will use an
8” dado on a 10” table saw and in fact, that’s the only size
most manufacturers make – with a 5/8” arbor bore. For the
industrial market, a few companies like SystiMatic make a selection
with larger sizes and 1” bore, but you’ll need a pretty
powerful, heavy saw to use it. A 10” SystiMatic dado weighs in at
over 10 pounds and cuts a lot of material.
Another exception may be a highly specialized use, by a very
knowledgeable professional, such as the one I heard about not long
ago where they were using an 8” non-ferrous blade on a 10” or
12” table saw to cut aluminum plate. This was a blade designed for
cutting extrusions, not solid aluminum, but these guys understand
the geometry and use it to their advantage.
Purpose or Material
This one can be problematic if you’re trying to buy a blade at
Home Depot, Lowe’s or ACE where all they sell is blades for
cutting wood on hand-held saws (Skil, etc.), table saws and miter
saws. But if you’re shopping online or at a saw shop or good tool
store, you can find specialty blades listed by purpose and material
or ask someone who knows what you’re talking about. And believe
me, it’s important to buy a blade designed for what you want to
The price of a 24 tooth rip blade might look attractive but if you
try to crosscut with it you won’t be happy. Conversely, try to rip
solid wood with a trim blade and you’ll burn more wood than you
cut. Use either blade to cut laminate flooring and you’ll regret
it when the top layer chips and the blade gets dull after three
cuts. Laminate flooring, like Pergo, is very hard and has aluminum
oxide in it – use an aluminum-cutting blade.
Manufacturers of saw blades that make blades for the professional
make several different blades, with different configurations, for
different uses and they identify them accordingly. There’s no need
for me to list them here, just stick with their recommendations and
you shouldn’t have any problems.
Type of Saw
Different types of power saws work best with blades made for them,
and can work horribly (if at all) with the wrong blade. Using the
example of a rip blade again: put a rip blade on a radial arm saw
and even if you rotate the carriage to rip, it’s going to want to
lift the wood up off the table. Try to crosscut with anything
vaguely resembling a rip blade (aggressive rake/hook angle) on that
same saw and the whole carriage will try to “run” straight out
at you. And the teeth will dig in and bind up your saw, tripping a
breaker. Been there and done that one before I knew there was such a
thing as a radial arm blade.
There are some types of blades, such as metal cutting blades, that
can be used on and are recommended for all types of saws: table saw,
miter saw and radial arm. Also some moderate-rake/hook combination
blades. But a good rule of thumb is to just stick to what the
manufacturer recommends. Buy a table saw blade for a table saw, a
miter blade for a miter saw and a radial arm blade for a radial arm.
When you think about it, you’re not going to be cutting sheets of
plywood on a miter or radial arm and you’re probably not going to
be mitering moldings on a table saw.
Most people understand this one, for the most part. Generally
speaking, you want a higher tooth count for cleaner, finish cuts, no
matter what the material. You want fewer teeth for thicker material.
Think of crown molding versus a 2 by 4. But if you’re a hobbyist
or homeowner doing odd jobs (like yours truly) you’ll want a
compromise blade, something you can use to reasonably cut a 2 by 4
or trim. On a miter saw or radial arm, 60 is a good number: 40 will
tear out on trim work and 80 will have to fight through a 2 by 4. On
a table saw, it’s a little more forgiving: 40 to 50 is what
you’ll find on good combination blades, like the famous Forrest
Woodworker, the TENRYU Gold Medal or the SystiMatic GP or Budke
Combination. Virtually all manufacturers make combination table saw
blades with tooth counts in this range so obviously it works.
By the way, as usual there are exceptions to this rule, especially
when it comes to cutting plastics. And it depends on the type of
plastic, whether it’s hard and brittle, soft and with a low
melting point or in between. Too many teeth will cause melting,
which will load or gum up the teeth, thereby giving you a very poor
cut. Not enough teeth, particularly in a hard plastic, will chip
Tooth Design and Configuration
This is the one topic that can be most confusing and the one where
you might, in some cases, find conflicting theories and/or claims
from different manufacturers. Not to say one is right and the other
is wrong, sometimes two completely different designs will work
equally as well for a job. For example: SystiMatic uses a triple
chip for plastic and TENRYU uses alternating top/alternating face.
But I suppose I should simplify this before confusing you more.
If you’d rather see this part in a more visual format, click here:
Alternating Top Bevel – ATB This is by far the most common
carbide tooth configuration, used for cutting solid wood, plywood
and particle board. Further, there are several variations on the
design that turn it into a specialist:
ATB w/Raker – ATBR Commonly called a “planer” blade or
“planer combination” this combines usually four ATB teeth with
one flat-top raker tooth for cleaning out the cut. It makes a true
multi-purpose blade for your table saw, whether cutting plywood,
crosscutting or ripping. A further variation on this one is a
specialized plywood blade that uses more (like 10) ATB teeth for
Alternating Top Alternating Face – ATAF Very, very smooth
crosscuts, with the outer edge of the tooth face planing the
material as the blade cuts through. Also good for Melamine and
veneered plywood. And as mentioned, TENRYU uses this for their
plastic blades, too. Put one on a miter saw and get great cuts in
wood and plastic, both. A variation on this one is to add a raker
every few teeth to clean out the cut. It would be called ATAFR, of
High or Steep Alternating Top Bevel – HATB This tooth
shape, combined with a negative or neutral hook or rake angle, is
used when you need a real knife-like edge to cut through Melamine or
fine veneers. Also sometimes used with a positive hook for
eliminating tear-out when crosscutting trim. The drawback to this
type of tooth is that the quality of your cut depends on very
pointed teeth and the more pointed they are, the faster they dull.
Triple Chip Grind – TCG This is a versatile tooth shape but
the primary purpose is for cutting hard materials, like aluminum,
laminate flooring, hardwoods and “solid surface” such as Corian.
It incorporates flat top raker teeth with what look like a flat top
teeth with the corners ground off at an angle. Without using sharp
points like ATB or ATAF blades, a TCG blade will last much longer
and handle the high impact of cutting hard stock. Manufacturers
combine this shape with different hook/rake angles to specialize
blades, from negative hook angles on non-ferrous blades to very
aggressive hooks on rip blades. Drawback: may tend to tear out when
crosscutting softer wood like pine or hemlock.
Flat Top Grind – FTG Flat top grind teeth, when used alone,
have only one purpose: cutting wood with the grain. Ripping. And
they’ve lost popularity in that use, too, as more manufacturers
are using TCG and ATB teeth to give rip cuts smooth enough they
don’t need to be run through a jointer to glue up joints. But
you’ve seen how other designs incorporate flat top teeth into
doing their job well.
Others - Some manufacturers use some highly specialized tooth
shapes for their more specialized, exotic blades but we won’t need
to go into those here. They’re far from basic and anyone who needs
one of those probably knows more about it than anyone.
Rake or Hook Angles
When considering a blade for your particular type of saw, this is
sometimes the most important consideration. And when combined with
tooth shapes and configurations, the factor of rake angle can change
a blade’s entire purpose.
Where the saw is concerned, you don’t want to use a positive hook
on a radial arm (some manufacturers rate their combination blades
for them but they’re not aggressive hooks) and a miter saw works
best with negative, neutral or moderately positive hooks –
depending on what you’re cutting.
Where material is concerned, generally harder materials require a
negative hook or no (neutral) hook angle. And if wood is prone to
tearing out when crosscutting, like softer conifer wood, a negative
hook is better.
So what is rake or hook angle? Lay a straight edge across a saw
blade, intersecting the arbor hole and look at the relationship of
the carbide tip to the straight edge. If the top of the tip leans
toward the edge, that’s a positive hook or rake. If it leans back
away from it, that’s negative. If it’s parallel to it that’s
neutral or a zero hook.
I hope this helps
clarify saw blade selection for you!
Owen Johnson, 2008