As a homeowner, you'll likely run into a project requiring a circular saw. Here's your ultimate guide to the tool, along with step-by-step tips for properly (and safely!) using one.
Don't let fear get in the way of your next DIY. Learning how to use a circular saw isn't as difficult (or scary) as it seems. Our tutorial shows you exactly how to use a circular saw, plus offers tips for making the most of this versatile tool. You'll learn how to secure your material, replace the blade, prep for a cut, and much more.
Circular saws are mainly used for cutting wood, but they can cut different materials with specialized blades. Like most tools, they can be bought for either left or right handed individuals. You'll probably use a circular saw more than any other tool for big projects such as deck building. A saw with a 7-1/4-inch blade and a motor that draws 10 to 13 amps is powerful enough to cut effortlessly through 2x stock, even at a 45-degree angle.
Most saws will come equipped with a combination blade for making crosscuts and rip cuts. If yours has a standard steel blade, replace it with a carbide-tipped combination blade. Inexpensive steel blades will be dull after about four hours of heavy cutting. A moderately priced carbide blade will last a long time and make cleaner cuts throughout its life.
You can accomplish many of your cuts (especially framing cuts) freehand, but for more precision, support the workpiece solidly and employ jigs or guides for cuts. Supporting the board will minimize dangerous kickback and splintering along the bottom face as the waste falls away. For all cuts, start the saw off the cut and push the blade into the board with a steady forward motion.
If you're not ready to commit to your own circular saw, test one out through a rental program at your local hardware store.
Cutting lumber, especially pressure-treated stock, calls for protection. Protect your eyes from flying chips and sawdust with safety glasses. If you are sensitive to pressure-treated lumber, use a facemask. When making frequent cuts, wear ear protectors.
Protect yourself from kickback, too. When the teeth on the rear of a circular saw blade catch or the blade binds in the kerf, the saw can kick back out of its cut line, ruining the cut and endangering the carpenter. Here are some ways to avoid kickback:
With your pencil and ruler, measure and mark the lumber in accordance with where you plan to cut. This line is the path the blade will follow, so make sure it's straight and accurate.
Make sure that your work surface—such as sawhorses or a saw table—will suspend the material. This prevents the blade from coming in contact with anything other than the material you're cutting. Then clamp your material to the work surface.
Choose the correct blade for your material. Typically, the more teeth a blade has, the finer the cut. Thus, if you're making very clean, precise cuts you'll want to use a higher-tooth blade. But if you're making rough cuts, a lower-tooth blade works just fine. If you're planning to cut stone, brick, or concrete, you'll need a masonry blade. And to cut metal you'll need a metal-specific cutting blade.
To install the blade, unplug the saw, push in the lock button, and push back the safety guard. When you're sure the blade is locked, remove the bolt and lift off the blade. Install the new one by pressing the lock button, sliding the blade inside the saw, and reattaching the bolt.
Get ready to saw by setting the depth requirement and, if needed, adjust the tilt for your board. Make sure the saw guard is down. Then look down the right side of the blade and line it up with your drawn line. This ensures a straight cut. Also check that the guide notch lines up with your mark.
Turn on the saw and let it reach full speed. Pushing the saw at an even pressure, slowly move it along the mark. Be careful not to push too hard—this could cause the blade to bind.
Editor's Tip: The direction you cut depends on the desired result. If you're making a rip cut, saw with the grain. For a cross-cut, saw against the grain.
Not all circular saw cuts are created equal. Some cuts are freehanded while others require a guide, and the angle or type of lumber you use can also affect the end result. The following are seven of the most common cuts. We'll identify each cut plus offer tips for making one:
Cutting Freehand: Rest the edge of the board on a solid surface and tilt it up 30 to 45 degrees, keeping the saw guide or the blade visible. Line up the blade with your cut line, start the saw, and let gravity pull it down the line. Keep the saw plate flat on the stock as you cut.
Crosscutting with a Guide: Clamp a layout square with its heel plate against the edge of the board, positioned to put the saw blade just on the waste side of the cut. Most saw plates are marked with the distance from the edge to the blade. Put the saw plate flat on the board, start the saw, and push it forward.
Cutting Miters: Clamp a layout square to the board as a guide. (Experiment to find the right distance away from the cut line.) Retract the blade guard before starting. The saw might work hard in a miter cut—don't push too hard. Cut the miter before you cut the board to length so you can recut if you make a mistake.
Rip Cutting: To make a rip cut, fit the saw with a rip guide. If the cut is not parallel to the edge of a board, either cut it freehand or clamp a long straightedge as a guide. Don't force the saw away from the cut—the rip guide might flex with it.
Bevel Cutting: Bevel cuts will make the saw work harder, so clamp the board firmly to a work surface using a guide set so the blade will cut along the waste side of the line. Set the bevel gauge to the correct angle and check it with a protractor. Start the saw and ease it into the cut with a slow but constant speed.
Cutting Long Stock: Support the board so the saw won't bind or kick back and to keep the board from splintering as the waste falls away. If the waste side is longer than 2 feet, support the board in four places. That way both sides of the cut will stay put and you can make a straight, neat cut.
Cutting Thick Stock: Mark the cut on one side of the piece and transfer the mark to the adjoining sides with a square. Position the saw to the waste side of the line and against a layout square. Push the saw through the cut from one end to the other. Turn the stock and cut each adjacent side. Transfer the cut line to two adjacent sides, and keeping both lines visible, position a reciprocating saw with the saw shoe against the stock. Keep the blade in line with the waste side of the cut and off the wood. Start the saw, and rock it back and forth through the lines.
As with any saw, proper maintenance will help prolong the life, accuracy, and safety of the tool. These common practices will keep your circular saw looking (and working) its best:
Squaring the Blade: Don't trust the bevel guide on a circular saw; it could be off by several degrees, producing non-square cuts. To guarantee accuracy, check the blade angle with a square, and adjust the plate until it's 90 degrees to the blade. Unplug the saw anytime you adjust the saw.
Changing the Blade: A dull saw blade is more dangerous than a sharp one. When you notice resistance or binding, it's time for a blade change. Unplug the saw and retract the blade guard. Set the teeth of the blade firmly into a piece of scrap or the top of your outside work surface. Make sure the board won't move. Remove the bolt and tilt the blade out. Reverse the procedure to install the blade.
Setting the Cut Depth: For best results and to reduce the risk of injury, set the blade to extend no more than 1/4 inch through the thickness of the stock. Release the saw plate latch to position the plate to the proper depth.
Choosing Board Sides: A circular saw blade exits the cut upward and will splinter the top of the board. Where appearance matters, cut with the good side of the board down.