Circular Saw Basics
Circular saws make quick, straight cuts across a board (crosscuts) or along the board’s length (rip cuts). You can also set a circular saw to make bevel cuts. Standard components on a circular saw include:
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- A blade guard that covers the blade when the saw isn’t in use and retracts to expose the blade during use
- A foot plate or shoe that steadies the saw against the work piece
- A depth adjustment to allow for work pieces of different thicknesses
- A bevel adjustment that lets the foot plate tilt in relation to the blade for making bevel cuts
Circular saw sizes are usually classified by the diameter of their blades. Sizes of 5-1/2 to 7-1/4 inches are the most common. There are also many options available on circular saws. Choose the best circular saw for your specific needs.
There are two basic designs:
- Sidewinder or inline saws are the most common and traditional circular saws. The motor is located along the same axis as the blade. A shaft runs directly from the motor to drive the blade. Sidewinder saws are more compact and lightweight than worm drive saws. They’re well suited to most circular saw applications.
- Worm drive saws have their motors positioned at a right angle to the saw blade. The motor uses gears to increase the torque transferred to the blade, making the worm drive saw well suited for heavy-duty use. Worm drive saws are longer and tend to be quieter than sidewinder saws.
Circular saws can make various types of cuts. Watch our DIY Basics video: What’s That Cut Called?
Where and how you use your circular saw will help determine the power supply you need. Two types are available:
- Cordless circular saws are convenient when working in areas where extension cords are difficult to use. Since they’re smaller than most corded saws, they work well in confined spaces. Cordless saws are best suited to cutting wood and wood products due to their battery limitations. While they can cut tough materials, the extra power needed for those applications drains batteries quickly. Cordless saws typically range in size from 5-3/8 to 6-1/2 inches.
- Corded circular saws don’t depend on batteries for power and are better suited for tough cutting jobs, such as masonry, steel and continuous woodcutting. Corded saws are available in many sizes; the most common is 7-1/4 inches. A corded circular saw requires a suitable extension cord. Follow the device manufacturer’s recommendations for compatible extension cords and see Power Cord Safety Tips.
Always unplug corded power tools and disconnect the battery on cordless power tools before servicing them.
- Blade capacity determines the maximum depth of cut a saw can achieve. The larger the blade, the deeper the cut. The most common blade diameter is 7-1/4 inches. Most saws with blade capacities of 6 inches or more can cut through 2-inch dimensional lumber at a 45-degree angle in a single pass. A 5-3/8-inch saw can cut through 2-inch dimensional lumber in one pass at 90 degrees but requires two passes at 45 degrees. As a general rule, a mini circular saw or multi-function circular saw is easier to control because it weighs less.
- Electric brakes reverse the flow of electricity in the saw motor when the trigger is released. Reversing the current stops the blade’s momentum quickly. Electric brakes can stop the blade in as little as two seconds — much quicker than a blade on a saw without this feature.
- Spindle or shaft locks make it easier to change the saw blade. The shaft lock immobilizes the shaft and blade, making it much easier to change the blade.
- Bevel capacity indicates the maximum bevel cut the saw can make.
- Bevel stops are presets that allow quick adjustments for bevel cuts.
- Laser guides help improve cutting accuracy by projecting a beam of light onto the work piece.
Caution
Always unplug corded power tools and disconnect the battery on cordless power tools before servicing them.
Which Circular Saw Blades Do I Need?
Handheld circular saws, table saws and miter saws are common do-it-yourself tools that use circular saw blades. These blades are typically designed for cutting wood or wood composites. You can also find blades for circular saws, miter saws and table saws that cut plastic, vinyl and more.
As you’re looking at blades for these tools, keep these general tips in mind:
- Blades with fewer teeth cut faster, but those with more teeth create a finer finish.
- Gullets between the teeth remove chips from the work piece. Deeper gullets often mean more aggressive teeth and faster cutting.
- Expansion slots help prevent warping as a blade heats and cools during use. They also reduce vibration, creating a straighter cut.
Other power saws also utilize circular blades, including
- Tile saws
- Concrete saws
- Chop saws
- Grinders
We’ll show you several types of circular saw blades below, starting with standard blades you’d commonly use with a handheld saw, miter saw or table saw.
Good to Know
Table saw blades and miter saw blades have a similar design to handheld saw blades but have a larger diameter.
Rip-cut blades are best for cutting along the grain of the wood (usually along the length of a board). You might use one of these blades when you’re reducing the width of a board.
- For use on wood, but will cause excessive splintering on plywood
- Usually have 16 to 40 teeth designed to cut quickly and aggressively
- Have deep gullets that provide good chip removal
Crosscut blades are designed for cutting across the woodgrain (across the face of a board) as you would do when cutting a board to a particular length.
- For use on wood
- Usually have 40 to 80 teeth
- Feature smaller gullets than rip-cut blades
- Don’t cut as quickly as rip-cut blades but create cleaner edges
Combination blades are good general purpose blades. They can effectively make both rip cuts and crosscuts.
- For use on wood
- Have multiple groupings of teeth; each group with one tooth for ripping and four for crosscutting
- Have deep gullets for good chip removal
Framing blades are perfect for jobs where speed is important and the quality of the cut doesn’t matter.
- For use on wood, particularly dimensional lumber
- Effective for rough carpentry
- Have 18 to 24 teeth
As the name suggests, these blades are primarily designed for cutting plywood to size.
- For use on plywood to reduce splintering
- Have 100 teeth or more
- Cut slower than some blades but leave a cleaner finish
Demolition blades are another type of blade you’d use when speed and capability are more important than a clean cut.
- For use on dimensional lumber and plywood
- Have low tooth counts for fast, aggressive cutting
- Are often capable of cutting wood embedded with nails
- May have a narrow profile (thin kerf) for easier cutting and less material waste than other blades
These blades are designed for applications where the quality of the cut is most important, such as for cabinet building and joinery.
- Ideal for cutting wood, composite decking, melamine, plastic and vinyl
- Typically have 60 teeth or more
- Often have a narrow profile (thin kerf) for easier cutting and less material waste than other blades
Tip
Blade diameter, arbor hole size, number of teeth and kerf (the thickness of the cut the blade creates) are typically printed on the face of a circular saw blade. You may also see a list of appropriate tool types as well as maximum revolutions per minute (RPM) and application specifications.
Continuous-rim blades are usually a type of diamond-edged blade — sometimes called diamond blades.
- For use on materials like tile and slate
- Don’t have teeth and gullets like a standard circular saw blade
- Have diamonds affixed to the blade edge
- Create a very clean finish
- Available for dry-cutting only, wet-cutting only or for both applications
Caution
While some blades are suitable for wet and dry applications, make sure your saw is suitable for the type of cutting you need to do.
Turbo-rim blades are diamond blades similar to continuous-rim blades. They lack the teeth and gullets of standard blades but have a serrated rim.
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- Can cut materials like brick and concrete
- Cut more aggressively than continuous-rim blades but don’t leave as clean a finish
- For dry-cutting only or for both wet and dry applications
Segmented blades also typically cut with diamond edges but have a rim divided by gullets similar to those on a standard blade.
- Can cut tough materials like brick and concrete
- Have the most aggressive cut of the diamond blade types
- Cut more quickly than the other diamond blade types but leave a rough finish
- For dry-cutting only or for both wet and dry applications
Like diamond blades, abrasive blades don’t have teeth. They cut with an abrasive material, such as aluminum oxide.
- Can cut materials like brick and concrete
- Depending on the blade, may be suitable as a metal-cutting circular saw blade
Stacked dado blades are woodcutting accessories designed for use on table saws or miter saws.
- For use on wood
- Include two circular saw blades as well as several chipper blades and shims
- Use to cut grooves (dados) in wood to receive another piece of wood, such as for shelves on a bookcase
- Different combinations of blades and shims create grooves of different widths
Caution
Follow the blade and saw manufacturers' instructions for use and safety.
Which Circular Saw Blade is Right for My Power Saw?
Each type of circular saw blade is designed to cut different material and work with specific power saws. Be certain the blade you choose is suitable for the material you need to cut and that it fits your saw. Your saw manual should provide information on compatible blades, but here are some quick tips.
- Handheld circular saws typically accept blades 4-1/2 inches to 7-1/4 inches in diameter. The teeth are often carbide tipped to stay sharp longer.
- Tile saws most often use 7-inch or 10-inch diamond blades.
- Table saws and compound miter saws use blades 8-1/4 inches or 10 inches in diameter. Like those for handheld saws, the blades are usually carbide tipped.
- Miter saws are usually designed for 7-1/4-inch, 10-inch or 12-inch blades. These blades are also usually carbide tipped.
- Circular saw blades for metal, such as those for use on metal-cutting chop saws — also called abrasive saws or cut-off saws — are often 14-inch aluminum oxide abrasive blades or carbide-tipped toothed blades.
Check the size of the arbor hole, or the hole in the center of the blade. It must fit the arbor or shaft on your saw. Some blades with a circular arbor hole include a piece you can knock out to allow them to fit saws with a diamond-shaped arbor.
Check the maximum RPM rating of the blade to make sure it’s compatible with the tool you plan to use.
Learn how to choose the best power saw for your projects:
- Table Saw Buying Guide
- Compound Miter Saw Buying Guide
- Garage Tool Storage Buying Guide
The steps for changing a circular saw blade will vary by tool type. You should always refer to your saw manual for specific instructions on changing a blade, but here are some general tips for changing a blade on a handheld circular saw:
- Unplug the tool or disconnect the battery.
- Engage the blade lock button on the saw.
- Fit the included blade wrench onto the head of the blade stud or arbor. You may need to use the wrench to rotate the blade slightly to let the blade lock fully set.
- With the blade immobilized, turn the wrench counterclockwise to loosen and remove the stud and the outer blade washer.
- Carefully move the lower blade guard out of the way and remove the blade through the slot in the saw foot or base.
- Position the new blade to rotate in the correct direction and slide it up through the slot and onto the blade shaft, against the inner blade washer.
- Make sure the outer washer is in place and install the blade stud. Turn the stud clockwise by hand until it’s finger tight. Lock the blade and use the included wrench to tighten it slightly according to the manufacturer’s instructions (for example, 1/8 turn or to specific guide markings). Don’t overtighten.
Caution
Wear heavy-duty work gloves when handling the saw blade.
When loosening and tightening the blade stud, use only the included wrench. Other wrenches may overtighten the stud.
If you need to sharpen a circular saw blade, take it to a professional. Sharpening some blades require specialty tools that most do-it-yourselfers don’t have. Attempting to sharpen other types of circular saw blades yourself risks ruining the blades.
To reduce the need to sharpen your blades, look for carbide-tipped blades. They’re more expensive than other blades, but they stay sharp much longer than steel or high-speed steel blades.
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More so than the brand of saw blade, getting the correct type of blade determines whether you'll get a quality cut. And in most instances, your new tool's factory-supplied blade may be better suited for job-site cutting than woodworking. Here are eight things you need to know to get the right blade for the job.
■ Diameter. Okay, this one's easy. Each tool generally accepts a specific size blade: typically 10" for tablesaws, 61⁄2 " or 71⁄4 " for handheld circular saws, 10" or 12" for mitersaws and radial-arm saws. Some tools can use a smaller blade (see dado blades, below), but never attempt to use a larger one. It might be difficult to find replacement blades in some sizes; your tool-buying decisions may hinge on the availability of blades.
■ Kerf. This refers to the width of the cut made by a blade. The thicker the blade, the less likely it is to flex (and the wider the kerf). So, heavy-duty stationary tablesaws generally use 1⁄8 "-kerf blades because those saws can easily power that blade through dense hardwoods. Tablesaws with motors rated at 11⁄2 hp or less, as well as mitersaws and radial-arm saws, get more apparent power with thin-kerf blades (about 3⁄32 "). Portable circular saws—especially battery-powered ones—use even thinner blades; it's almost impossible to find 1⁄8 "-kerf blades for portable saws. These ultrathin blades put less strain on the saw motor and because of their smaller diameters don't flex noticeably.
■Tooth grind. Almost every blade used today has carbide teeth, which stay sharp far longer than all-steel blades. Manufacturers grind the teeth to the shape best suited for a specific cutting action. If you look into the face of the teeth (as shown below), you'll see the tooth grind. An alternate-top-bevel (ATB) grind has teeth with alternating left- and right-pointing tips, made to minimize tear-out in wood and veneered plywood. General purpose, crosscutting, and plywood/melamine blades use this grind.
Rip blades, used to cut wood parallel to the grain, have flat-top teeth with no bevel. This helps clear debris from the kerf. Combination blades use a mix of ATB teeth and flat-topped teeth, and do better at crosscutting than general-purpose blades, but don't rip as well. Blades used primarily to cut solid-surface countertops and melamine-coated particleboard use a triple-chip grind to prevent tear-out.
■ Hook angle. This refers to the angle of the tooth face, as viewed from the side. As shown below, if you draw a line from the center of the arbor hole to the leading edge of a tooth, you'll see its positive (leaning forward) or negative (leaning backward) hook angle. The more positive the angle, the more aggressively the blade cuts. Use a high positive hook angle (5° to 20°) on a tablesaw for general crosscutting and ripping, and a steeper angle (up to 30°) for cutting melamine-coated particleboard and veneered plywood.
Sliding mitersaws and radial-arm saws require a negative hook angle (-5° to -10°) to reduce the saw's tendency to lurch forward too quickly during a cut. Portable circular saws and non-sliding mitersaws work best with blades that have a hook angle of 5° to 0°. But be aware: Not all blade manufacturers list the hook angle on their blades or packaging, so do your research before buying.
■ Tooth count. Although general-purpose and combination blades work well at multiple tablesaw tasks, you'll get the best results by choosing the right blade based on its number of teeth. Tablesaw rip blades have 24–30 teeth, with deep gullets for waste removal. Crosscutting blades have high tooth counts: 60–80 are best for tablesaws, 10" mitersaws, and radial-arm saws; 80–100 for 12" mitersaws and radial-arm saws. Cutting plywood on a tablesaw calls for an 80-tooth blade. Portable circular saws rip best with 10–12-tooth blades, crosscut best with 40 teeth, and cut veneered plywood best with 60 teeth.
■ Dado blades. Tablesaws (and some radial-arm saws) accept a stacked dado set, shown below, for cutting one-pass dadoes, grooves, and rabbets up to 7⁄8 " wide, depending on the machine. These sets consist of two outer blades (one with left-beveled teeth and the other beveled to the right) and inner chipper blades (with flat topped teeth). Stack any combination of chippers between the outer blades to get the channel width you need.
■ Arbor hole. The hole in the center of each blade is sized to match the arbor (blade-drive shaft) of your saw. Most blades 10" or less in diameter mount on a 5⁄8 " arbor, but 12" blades use a 1" arbor. And many saws manufactured by Skilsaw use a proprietary diamond-shaped mounting system, below.
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