Explanatory notes
… grinding, pulping, etc., (e.g., for milling grain (upper or lower stones); pulping wood, asbestos, etc.; paper-makers’ … tools, etc. , and designed for mounting on hand, pedal or power operated machines. The grindstones and millstones … their fixation in the body of the hone. It should, however, be noted that certain abrasive tools are excluded …