Magna-TipA(R) Bit Shaping Stone - Large Stone

Special stones for custom-shaping MAGNA-TIP and Brownells Fixed Blade screwdrivers. To shape tips, chuck stone into drill press, lock bit or screwdriver into drill press vise and grind to match screw slot. Large stone fits the radius of the hollow grind on both screwdriver models. Mfg: Brownells SPECS: A 1/4'''' (6.35mm) shank. 25,000 rpm. Large - 1-9/16" (3.97cm) dia. x A 1/2'''' (12.4mm) thick. Small - 5/8'''' (15.0mm) diameter x A 1/2'''' (12.4mm) thick.