How to Use a Speed Square
How can a single piece of heavy-gauge aluminum with no moving parts attract so many fervent fans? A Speed Square’s true secret lies in the dense congregation of information and features packed on its face: a lipped fence, deeply incised numbers, holes, notches, and cut-outs. It’s these features that make this a highly functional yet very low-cost tool for scribing, marking, and cutting. The accompanying 60-page “Swanson’s Little Blue Book” is legendary in fine carpentry and roofing trades for helping to translate the Speed Square measurements to real-world applications. Use as a Saw Guide: Lip the Speed Square fence over the side of the board and cut against the square with a power saw. Square a Power Saw Blade: Unplug the saw and rest the square against the side of the blade to adjust the blade to 90 degrees. Find the Width of a 2x4: The diamond-shaped hole is 3 1/2 inches from the end—the true width of 2x4s. Measure Between 0 and 6 Inches: Hook the lip of the square over the board. The numbers above the “Swanson Speed Square” insignia will produce the measurement. T-Shaped End: Hang this t-shaped end over the side of a board. Or use it as a stand for letting the Speed Square stand up by itself. Numbers 1-6 on the Side: These are inch marks and inch numbers. Note that a Speed Square actually measures up to 7 inches, not 6 inches. The 7th inch is the very end of the tool and is unmarked. Diamond-Shaped Hole: This hole is 3 1/2 inches from the end. It is a helpful quick measurement since the width of 2x4s is actually 3 1/2 inches, not 4 inches. Numbers 5-80 on the Long Side: These are angle degree numbers, not inch marks and numbers. Degrees between 0 and 5 are not marked with numbers, nor are degrees above 80 degrees. You can always haul out your electric miter saw or hunt for the manual miter box, but with the Speed Square, you can lay the square against the trim and create quick 45-degree pencil marks with the square. Do not cut directly against the square. Instead, remove the square and cut by following the line. If you don’t have or can’t find your bubble or laser level, you can use the Speed Square for this, but you will need to have a string, twine, or chalk line on hand. Remarkably, using a Speed Square can be preferable to using a bubble level because you can measure the exact deviation down to the degree. On the Speed Square, locate the groove marked as ‘Pivot." Place the Speed Square on the material with the pivot end up. Drape a string (such as a chalk snap line) over the Speed Square, resting it in the pivot groove. Weight the hanging end of the string with a light weight such as a bolt. If the work material is level, the string will hit the 45-degree mark. The ability to squarely cut 2x4s is a classic Speed Square maneuver and is well worth the price of the tool just for this. Rest the square’s lipped fence over the 2x4. Hold the square firmly. Cut against the square with a power saw, making sure that the saw’s fence slides along the square’s fence. Do not let the saw blade run against the square. Lay the Speed Square on the board, with the lipped fence over the edge. Place your pencil in the Speed Square’s so-called Diamond cutout (for 3 1/2 inches) or in 1 of the 10 notches located in the triangular cutout (for 3/8-inch to 3 inches). Use a regular pencil, not a carpenter’s pencil. Slide the square down the length of the board, drawing the line as you go. Because the Speed Square is so versatile, you may forget that it is still a square. A Speed Square is best at squaring up smaller, shorter things rather than walls because it is only 7 inches long (though Swanson also does offer a 12-inch version). For squaring up walls and rooms, you need at least a carpenter’s square. Better yet is a laser level that casts an “X” mark. Place the Speed Square against the two elements (such as wall and cabinet). If there is a gap, this means that the two elements are not square with each other. With the tool unplugged, rest one side of the Speed Square against the side of the blade. The other side of the square should rest against the bottom of the saw. Readjust the saw so that it is square against both sides of the Speed Square.
