7 machine tools and tools for machine tools, namely, grinding wheels, grinders, polishers not for use on floors, drills, mills, and tools used for grinding, cut-off grinding, polishing, cutting, drilling, core drilling, brushing and milling; dressing and profiling tools for grinding wheels used as components of machine tools; power-operated coated revolving abrasive belts and flap discs; and brushes being parts of motors and generators