More aggressive than diamond grinding bits stone grinding bits sanding drum sanding bits. Used for 3-jaw chuck drill (not optimal) and high speed rotary tool (optimal). A must-have versatile shape tungsten carbide burr bits kit cutting bits grinding bits carving bit engraving bits deburring bits drill bits for hard metal steel aluminum stone wood plastic. 3. Perfect for tight spaces than grinding wheel and grinding discs, great for detail work. For lots of materials removal please use our larger shank burrs bits and 500W+ rotary tool. 6 years returnless replacement.