By Paul Bianchina
Squares make up a group of tools that are indispensable to carpenters, woodworkers, tile setters, machinists, and anyone else who needs to make certain their projects are, well, square. Found in just about every well-equipped toolbox and workbench, squares come in wide variety of shapes and sizes, depending on their intended use.
- Try Square: Try squares are L-shaped, with a thin metal blade that is marked in graduations like a ruler and a "handle," called the body, which is thicker than the blade. For woodworking, the body is typically made of wood, while machinists use a variation that has a metal body.
Try squares are used primarily to mark a straight line across a piece of wood for cutting. The thicker body of the square is placed against the edge of a piece of wood and the blade is placed on top of the wood, which ensures that the blade is then exactly perpendicular to the edge of the board. The thicker body of the try square also allows it to be placed flat on a table or tool with the blade sticking up in the air, making this a useful tool for measuring things, such as the height of a table saw blade or router bit.
- Combination and Sliding Squares: These are similar to try squares, in that the body is thicker than the blade. Sliding squares, however, have a body that slides along the length of the blade by setting the blade to a specific distance away from the body, you can then place the body against the edge of the board and use the blade as a marking gauge. Combination squares also have a sliding body, but the body has both a 90-degree and a 45-degree side, so you can measure and mark both of these common angles.
- Framing Square: Very familiar to carpenters for many years, the framing square is used for a variety of carpentry and framing tasks. Framing squares are much larger than try squares, with one 24-inch-long leg and one 16-inch-long leg. The entire square is manufactured from one piece of metal to ensure durability and accuracy, and both legs are marked with standard inch and fraction graduations as well as a variety of tables and framing information.
Framing squares are used to mark angles for cutting rafters, and to mark stair layouts on rough stringers. Tables printed on the square specifically assist with these calculations, and an instruction sheet is usually included as well. In addition to these layout tasks, the large size of the framing square also makes it very useful for checking 90-degree angles inside and outside corners during many framing and finish carpentry operations.
- SPEED® Square: SPEED® Square is the trade name for a very popular type of square in wide use by carpenters. The SPEED® Square, also known generically as a rafter square, is triangular instead of L-shaped, and simplifies the marking of angles for cutting rafters. Unlike framing squares, which require that specific numbers on the two blades be used to set specific cutting angles, a SPEED® Square has angles marked on the tool for faster and easier set up of the various cuts used in roof framing. A booklet is included that explains the setups and use of the tool.
SPEED® Squares have another important use on the job site. Because of their design, which includes a projecting "lip" along one side of the tool, the square can be laid on top of a board and held tightly against the board's edge at the same time, in the same manner as a try square. This ensures that one side of the square is exactly 90-degrees to the edge of the board, allowing you to use it for marking cut lines and also as a guide for your circular saw while doing the actual cutting. The third side of the square is set at a 45-degree angle to the other two, allowing it also to be used as a marking and cutting guide for miters.
- OneDer Square: New on the market, the triangular OneDer Square is both large (12 inches on a side) and lightweight, made of high-impact plastic resin. The OneDer Square's design allows it to be used as a standard 90-degree and 45-degree square, as well as a rafter square for quickly laying out angled roof framing cuts. It also has two small built-in bubble vials that allow the square to double as a torpedo level. But where this unique tool really shines is as a cutting guide for sawing solid lumber and I-joists. A pivoting arm with an adjustable marking point allows for quick setups while adjusting for the width of the base plate on your circular saw. It's hard to understand until you see it in action, but the innovative design of this tool is both simple and accurate for anyone who regularly cuts lumber with a circular saw.
Squares of all types are readily available at tool shops, lumberyards, home centers, and hardware and department stores.
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