AA-Grade Granite Tri-Square 4-Face Four-Face Granite Tri-Squares provide an excellent, economical way for accurately checking the X-Y-Z axes on CNC machine tools and coordinate measuring machines. Lying in the horizontal position, the X and Y axes can be checked for 90º squareness. With the square in the vertical position, tracing along the vertical edge of the square can check the perpendicularity of the Z axis. Granite tri-squares may also be used in the same manner that steel squares would be used for the direct checking of squareness and straightness. 4-Face Tri-Square include 1 large face and 2 edges that are flat and square to each other, with lightening holes. Features include... Granite Dimensions are as follows... 12" Long 18" High 3" Wide AA Grade (.000050" Accuracy) Includes Certificate of Calibration traceable to NIST. # of lightening holes will vary with size of square. ISO 17025 Accredited Cert available at extra charge.
