Granite Accessories Three-Face Granite Tri-Squares Three-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. Laying 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. Toolmakers' Fla ts These handy flats are small precision surface plates that are ideal for many inspection and checking uses throughout the plant. They are especially well suited for layout work and offer an easy, portable reference for gaging small parts. Offered in Crystal Pink® or Black Granite, Starrett Toolmakers' Flats are 12" long x 8" wide x 2" thick (300 x 200 x 50mm) and finished to an overall tolerance of .0001" (0.0025mm). The shipping weight without case is 20 lb (9kg). Toolmakers' Flats EDP Description 81803 Crystal Pink® granite 81802 Black granite 81804 Sturdy felt lined case for toolmakers' flat Three-Face Granite Tri-Squares Accuracy Grade – EDP Dimensions (Length x Height x Thickness) Weight AA Laboratory .000025"/6" TIR (0.0006/150mm) A Inspection .000050"/6" TIR (0.0012/150mm) in mm lb kg 81969 81970 6 x 9 x 3 150 x 225 x 75 18 8 81961 81962 9 x 12 x 3 225 x 300 x 75 23 10 81964 81965 12 x 18 x 4 300 x 450 x 100 60 27 81967 81968 18 x 24 x 4 450 x 600 x 100 120 54 81971 81972 24 x 36 x 6 600 x 900 x 150 570 259 Other sizes quoted on application. Toolmarkers' Flat Tri-Square 418 G ranite S urface P roducts