Starrett 20 3 Hardened Steel Master Precision Square, 2 3/8" Beam Length, 3" Blade Length

Made of high quality tool steel Squareness accuracy to 0.0001" (0.0025mm) every 6" (150mm) The beam is grooved at the inner corner for clearance of burr or dirt Length of blade from the inner edge of the beam to the end of the blade