55 Master Precision Squares with Beveled Edges 1-1/2-6"/40-150MM These 55 Hardened Steel Squares are the same as the 20 Squares described above, except that the blades are beveled on both edges of each side, which provides an excellent visual line contact with the work. 20 Master Precision Squares 1-1/2-36"/40-910MM The finest precision-checking squares – not graduated. Squareness accuracy to .0001" (0.0025mm) every 6" (150mm). These hardened steel squares are used when extreme accuracy is required. The beams and blades are hardened, ground and lapped to ensure parallelism and straightness. The beam is grooved at the inner corner for clearance of burr or dirt. Made of high quality tool steel, with the finest of craftsmanship throughout. 20-3 55-3 Master Precision Squares 20 Master Precision Squares Squares Only Case Only Size – Length of Blade* Length of Beam Cat. No. EDP Cat. No. EDP in mm in mm 20-1 1/2 50128 916 55152 1-1/2 40 1-1/2 40 20-3 50130 951 55153 3 75 2-3/8 60 20-4 1/2 50132 918 55154 4-1/2 115 3 -1/2 90 20-6 50134 919 55155 6 150 4-5/16 110 20-6 W/SLC‡ 66899 20-12 50136 20ZZ-12 55156 12 300 7 180 20-12 W/SLC‡ 66900 20-24 50140 20ZZ-24† 55158 24 600 12-5/16 310 20-36** 50142 20ZZ-36† 55159 36 910 20 500 Larger squares can be furnished; quoted on application. * Length of blade from the inner edge of the beam to the end of the blade. ** 36" (910mm) and larger size squares have special screws to secure the blade to the beam. † Rack-type case. ‡ Includes redemption card for Standard Letter of Certification (SLC). 55 Master Precision Squares with Beveled Edges Squares Only Case Only Size – Length of Blade* Length of Beam Cat. No. EDP Cat. No. EDP in mm in mm 55-1 1/2 50277 916 55152 1-1/2 40 1-1/2 40 55-3 50279 951 55153 3 75 2-3/8 60 55-4 1/2 50281 918 55154 4-1/2 115 3-1/2 90 55-6 50283 919 55155 6 150 4-5/16 110 * Length of blade from the inner edge of the beam to the end of the blade. 277 starrett.com S quares