Squares
Squares are used to indicate if two surfaces of a part or assembly are perpendicular by visual comparison. Most squares consist of a simple, fixed standard with a beam and blade (or two surfaces) with a mutual orientation of 90 degrees. A wide variety of squares exist such as precision/solid square, cylindrical squares, adjustable universal / sliding bevel, adjustable die maker’s square, angle squares, double squares, try squares, "T" squares and combination squares.
Precision or solid squares consist of a short ground blade and a beam or handle section that form an "L" shape. The squares are precision ground and do not normally have any rulings. The square often has reliefs on the inside corners or outside edge to facilitate the fillets or radii on cast or machined parts. The beam is thicker compared to the blade, which facilitates location of the square on an edge. Solid squares are used for precision marking, measuring and checking squareness of components in machine shop settings.
Cylindrical squares have a hollow cylindrical shape and are commonly used to check other squares in machine shop or inspection room settings. Some cylindrical squares will provide graduations indicating the variation from square.
Universal bevels, sliding bevels, combination bevels, or T-bevels are used to transfer or duplicate angle measurements. Usually, bevels do not have any graduations.
Adjustable die makers’ squares are used to measure small angular variations (10 degrees) from square. These squares are commonly used for measuring angles, die clearances, and pattern drafts. They often come with different attachments such as offset, bevel, or ruled blades.
An angle square consists of a square with angular graduations along the longest face or hypotenuse.
Double precision squares have a square head that slides onto a blade or rule. The square head has two square surfaces and usually a variety of optional blade types such as bevel blades, drill point angle blades, and ruled blades.
Try squares consist of a short blade and a beam or handle section that form an "L" shape. The beam is thicker compared to the blade, which facilitates location of the square on an edge. "L" squares are used for general shop marking, measuring, and checking squareness of components.
"T" or dry wall squares have a long blade and a beam or handle section that forms the top of the "T" shape. The beam is thicker compared to the blade, which facilitates location of the square on an edge. "T" squares are used for marking, measuring and checking squareness of large flat sheets of materials such as drywall. "T" squares are available in fixed or folding versions.
Combination squares measure length, center, angular or squareness determination, and often have transfer or marking capability. These multiple tasks are possible because these sets have a series of optional heads (square, center or protractor).
