13E Double Square with bevel blade. 13, 13M Double Squares with Hardened Blades 4-6"/100-150MM These squares are very popular with machinists, toolmakers, and patternmakers. The sliding blades are adjustable making it practical for a wide variety of uses. The faces of the head are ground square, and the 6" (150mm) size has a level. The bevel blade is available, featuring an octagon angle 45º at one end and a hexagon angle 60º at the other end, clearly marked. A drill grinding blade, also available for 6" (150mm) squares, is beveled to 59º for drill grinding on one end and 41º (the cutting angle of countersinks for machine screws) at the other. Both ends have quick-reading 64ths grads. and the graduation is located to measure perpendicularly to the axis of the drill. By reading the graduations, the center point can be easily and accurately located. The 6" square head used with the drill grinding blade is approximately 3-1/2" (90mm) long, and the faces approximately 9/16" (14mm) wide. Double Squares Inch Reading Double Squares – 4R Graduation – 8ths, 16ths, 32nds, 64ths Cat. No. EDP Size Description 13A 50109 4" With graduated blade only 13C 50111 6" With graduated blade only 13E 50112 With graduated and bevel blades 13D 50114 Drill grinding blade only for 6" (150mm) squares Millimeter Reading Double Squares – mm Both Edges One Side; mm and 1/2mm Reverse Side Cat. No. EDP Size Description 13MA 56278 100mm With graduated blade only 13MB 56279 With graduated and bevel blades 13MC 56280 150mm With graduated blade only 13ME 56263 With graduated and bevel blades 279 starrett.com S quares