A Blade for All Seasons
Tablesaws occupy center stage in most shops: They're used for ripping and crosscutting hard and soft woods, plywood, tempered hardboard, and the occasional acrylic. You can even use the saw to joint an edge or resaw. With such diverse materials and cuts, selecting the right blade is essential to getting a clean, burn- and tear-out-free edge. Tablesaw blades come in a wide variety of styles and designs, but they generally fall into one of three categories: rip, crosscut, or general-purpose.
A typical 10" rip blade has 24–30 teeth, resulting in deep, wide gullets between each tooth that facilitate the removal of large amounts of material without clogging the blade or straining the saw's motor. The blades also rely on triple-chip grind or flat-top grind teeth (below) that cut efficiently with the grain. These blades work well when jointing edges or resawing thick stock.
When cutting across the grain, lots of small bites work better than fewer big ones, so the more teeth the better. Typically, these blades have 60–80 teeth and employ an alternate-top-bevel (ATB) tooth configuration, resulting in an exceptionally smooth finished edge with little if any end-grain tear-out. This is also the blade of choice for clean cuts in plywood.
In a perfect world, every shop would have one blade dedicated to ripping and another for crosscutting. Quality blades can be expensive, so this may not be an option for many woodworkers. (And some of us are too lazy to change blades all the time!) A good compromise is the combination or general-purpose saw blade. With 40–60 teeth, these blades provide very acceptable edges, whether crosscutting or ripping. Teeth generally are an ATB configuration, gullets are deep enough to carry away the larger chips, and expansion slots keep the blade cool during long rip cuts. Although these blades can't match all the performance characteristics of dedicated blades, they're still great alternatives.
The skinny on thin-kerf blades
When selecting a blade, consider the width of the kerf. A standard saw blade removes 1⁄8 " of material in a single pass. When cutting dense woods or thick stock, such a blade can cause a saw to labor, especially with a motor smaller than 3 hp. A thin-kerf blade, at just 3⁄32 "-thick, overcomes this by removing less material per pass, easing the strain on smaller motors. Plus, it conserves stock: That extra 1⁄32 " may pay off when making multiple cuts in expensive woods such as ebony or cocobolo.
Most blades can be purchased in either standard or thin-kerf configurations. But remember, the thickness of the blade must match the thickness of your saw's riving knife or splitter.
A clean blade is a happy blade. Learn how to remove pitch buildup and gum. woodmagazine.com/cleancutters.
Written by: Jim Heavey