A-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 A Grade (.0001" 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.
