A try square or try-square is a woodworking tool used for marking and checking 90° angles on pieces of wood.

To try a piece of wood is to check if the edges and faces are straight, flat, and square to one another.

[3] A try square is made of two key parts, the blade (also known as a beam or tongue) and the stock, which are fixed together at 90° to form an 'L' shape.

[7][2] A common form of try square has a broad blade made of steel that is riveted into a stable, dense tropical hardwood stock, often ebony or rosewood.

The inside of the wooden stock usually has a brass strip fixed to it to reduce wear.

[9] Historically squares have also been used by woodworkers, such as joiners and carpenters, as symbols in signs and heraldry to represent their trade.

[10] The square as a symbol is also seen in artistic representations of the Christian saints Thomas the Apostle and James the Less.