A Framing Square is a Key Tool in any Carpentry Project

By Mark J. Donovan

A framing square is an integral part of any carpenter’s tool set. It is used for a multitude of framing applications. Besides aiding in making 90o angle framing cuts, it is extremely useful in framing stairs and roofs.

A framing square is constructed out of steel or aluminum. It has two arms that are positioned at a right angle to each other. One of the arms is referred to as the blade and is two inches in width and 24 inches in length. The second arm is referred to as the tongue and is 1.5 inches in width and 14-18 inches in length. The corner of the framing square is referred to as the heel.

On each of the arms there is a stamped in graduated scale in inches. The scales are stamped on both sides of the square. On the face of the square (usually determined by the manufacturer’s label) the graduated scale is broken down to 1/8th and 1/16th intervals. On the back of the square the graduated scale is broken down to 1/12th of an inch intervals.

For homeowners who are looking to simply make right angle cuts the use of a framing square is fairly self evident. The blade of the framing square should be placed up to the edge of the lumber (e.g. 2x4) and the tongue should lie perpendicularly across the top of the lumber. A line can then be made along the length of the tongue and a straight perpendicular cut can then be made. The Stanley 45-300 Aluminum Carpenters Square is an excellent framing square for any framing application.

For framing stairs, hip roofs, or rafters a more in-depth understanding of how to use the framing square is required. A book on framing, such as the Graphic Guide to Frame Construction: Details for Builders and Designers (For Pros by Pros), can provide the detailed instructions for utilizing a framing squire for these applications.