Why and how to check the accuracy of your circular saw
Have you spent time checking the accuracy of your circular saw? Did you even know that you should?
Whether guiding against a rafter square or straightedge or just following a line freehand, your saw needs to be in tune for efficient cutting. That means having accurate cutline markers and the shoe set parallel with the blade.
Circular saws have two cutline marking notches, one for square cuts, or 90°, and another for 45° bevel cuts. To check the accuracy of your circular saw, start with the square-cut marker. Make sure the blade is set at exactly 90° to the saw shoe using the adjustable set screw and cut into a piece of wood a few inches guiding the saw against a square or straightedge.
Stop the blade and back the saw out of the cut while keeping it against the edge guide. See if the kerf made by the blade lines up with the marker. If it’s off…