A try square is a tool used in woodworking for marking and measuring a piece of wood. The square refers to the tool’s primary use of measuring the accuracy of a 90 degree right angle. A Try square can be used on a surface to check its straightness or correspondence to an adjoining surface.
A traditional try square has a broad blade made of steel that is riveted to a wooden handle or ‘stock’. The inside of the wooden stock usually has a brass strip fixed to it to reduce wear. Some blades also have graduations for measurement.
An alternative use of a try-square is to test the edge of a piece of wood to check how square it is. The try-square and material are held up to the light and the try-square is moved along the length of the wood. If light shines through any gaps between the blade and the wood, then the edge is not square.
The woodworkers try-square is composed of two main parts – the stock and the blade. The blade is made from hardened and tempered steel which makes is resistant to damage. The stock is usually made from timber such as rosewood although cheaper versions can be made from cheaper timbers or plastic.
A typical use of a woodworkers try-square The try-square is pushed against the straight edge of a piece of wood and a pencil or marking knife is then used to mark a straight line across the material. The line should be continued all the way round the timber on all four sides.
The Try square is sometimes spelled ‘tri square’ although its etymology is from ‘trying’, in the sense of testing, rather than the prefix ‘tri-‘ meaning three.
Accurate Try Squares can be very expensive. Australia has some excellent tool makers who produce woodworking try squares that are perfect and beautiful. Chris Vesper in Somerville makes squares that have a retractable tab in the stock that makes them convenient to use on the edges of boards. Colen Clenton has made precision try squares for many years. His squares have an adjustment mechanism that allows them to be re-calibrated if dropped.