FOR HAND TOUCH-UP OF TUNGSTEN CARBIDE AND HIGH SPEED STEEL CUTTING TOOLS * Next to diamond in hardness, yet less expensive than diamond tools and lasts far longer. * Sintered boron carbide grains are suspended in a tough resilient matrix which resists grain pull-out and premature separation. * Shapes and removes metal rapidly and cleanly. * Best for touch-up of Tungsten Carbide and HSS tools already set up in machine tools. No need to disturb setup. * One of the few honing tools you can really bear down on without fear of breakage. * Generous sized 1.6" Long stones. * Cemented into sturdy 7 long handle with a 2X magnifier. * Glaze easily cleaned off with an ordinary pencil eraser.