The Speed Square is one of the most underrated tools in most workshops. Even if you’re not an experienced craftsman, you’ve probably got one of these hanging around somewhere. Whether you wear yours on your hip while working or you have never heard of this triangular thing people are calling a square, there is a lot to appreciate about this handy tool.

Marking Angles

The speed square is designed as a 45-45-90 triangle, which means that the bottom foot and the flat side are perfectly 90 degrees to each other. This is helpful when marking a measured line on a board, aligning perpendicular work pieces, or adjusting saw blades to cut square and true. The other points on the speed square are great for marking out consistent 45 degree angles so you can cut some nice clean miter joints.

There are also several tick marks along the outer edge which helps you find angles that aren’t 45 or 90. Just place the foot against the flat edge of your workpiece and rotate the speed square (while keeping the 90 degree pivot point in place) until your desired angle matches up with the other edge of your board. Scribe a line using the flat edge and you’ve got an accurate angle.

Some speed squares have a little diamond stamp out near the ruler. This diamond helps you find a 90 angle from any previously scribed line. Just place the existing line inside the diamond along its long axis and the short axis is 90 degrees to it. This alignment allows you to mark a 90 degree line using the speed square’s straight side.

Temporary Saw Fence

When using a circular saw to cut dimensional lumber, you would love to have nice squared ends. The speed square helps you create a temporary fence for the foot of a circular saw to ride against when cutting. Just place the foot on the board’s long edge, move the speed square to the desired angle, clamp it down, and ride the saw against the speed square; boom, clean angled cuts.

Roofing Applications

Most speed squares also have other registration lines on them, some list HIP-VAL and COMMON markings. These indications are used to measure the pitch of roofing rafters at different intervals. These are used to find the pitch of “Common” rafters and “Hip-Valley” rafters over a 12″ distance.

Other Uses

Of course the speed square is equipped with a ruler, and some times, small notches that allow you mark line parallel with the speed square’s foot.  Just place a pencil in the notch, align the speed square’s foot to the workpiece and drag the speed square along the side. This creates a nice offset line parallel to the outer edge.

I hope this helped you just a little bit, and if you have any tips or trick that I didn’t mention, please let me and everyone around you, know. If you have any suggestions for future Bits segments, please let me know.