Cylindrical squares, used on surface plates, provide one of the most reliable 90° reference standards available in the industry today. Work may be placed against the periphery and sighted for checking squareness, right angle by comparison method. Master cylindrical squares are also used for checking the squareness of the vertical axis to the horizontal axis of numerically controlled machining centres. Luthra master cylindrical squares are made of high quality alloy steel, scientifically heat treated for maximum stability and wear resistance. The periphery is ground between centres straight and round within the tolerance specified for each size, with an extremely fine micro finish. The ends, recessed are ground and lapped square with the axis within the specified tolerances as per IS 6952:1990. Each square is packed in a finished wood case with hinged cover.
Luthra Cylindrical squares are supplied with calibration certificate traceable to National Physical Laboratory (NPL, Govt.Of India) New Delhi.