Explanatory notes
… grinding, pulping, etc., (e.g., for milling grain (upper or lower stones); pulping wood, asbestos, etc.; … flat, conical, spherical, dished, ring-shaped, recessed or stepped); they may also be planed or profiled at the edges. … etc., which retain their identity and function even after application of the abrasive material (i.e., tools which, …