13 DOUBLE SQUARES WITH HARDENED BLADES Popular with machinists, toolmakers, and patternmakers. The sliding blade is adjustable, making it practical for a wide variety of uses. The faces of the head are ground square. Fea tures • 4R Graduation – Quick Reading 8ths, 16ths, 32nds, 64ths SQUARES Cat. No. EDP Size 13A 50109 4" 13A 106 R ules and S quares