THIS FOWLER MAGNETIC V-BLOCK SET, MODEL 52-585-075, FEATURES PRECISION-GROUND CONTACT FACES AND POWERFUL, PERMANENT MAGNETS. EACH BLOCK MEASURES 2-3/8" WIDE X 4" LONG X 3-7/8" HIGH. THE V-HOLDER IS DESIGNED TO ADHERE TO ANY FLAT FERROUS SURFACE, ENABLING LIGHT MACHINING OPERATIONS SUCH AS GRINDING, BORING, AND TAPPING ON VARIED SHAPED WORKPIECES. THE FACES AND V ARE ACCURATELY GROUND, WITH A PARALLELISM AND SQUARENESS OF .0008" AND V CENTRAL TO .008". WORKING SURFACES ARE HARDENED TO 35-45 HRC. THE HOLDER APPLIES MAGNETIC FORCE ACROSS THE UPPER, LOWER, AND V-CHANNEL SURFACES, WHICH CAN BE ENGAGED OR DISENGAGED VIA A LEVER FOR EASY POSITIONING AND REMOVAL.