A try square is a woodworking tool used for marking and measuring a piece of wood. The Square refers to the primary use of the tool: measuring the accuracy of a right angle (90 degrees). A piece of wood that is rectangular, flat, and has all edges (faces, sides, and ends) 90 degrees is called four square. A board is often milled four square in preparation for using it in building furniture.
A traditional try square has a broad blade made of steel or brass that is riveted to a wooden handle. The inside of the wooden handle typically has a steel or brass strip fixed to it that is precisely 90 degrees to the blade. Some blades have either metric or enlish graduations for measurement.
See also