17 METAL CLAD PLASTICS FOR GENERAL USE IN THE INDUSTRIAL ARTS; PLASTIC SHEETS, TUBES, RODS AND MOLDED FORMS FOR GENERAL USE IN THE INDUSTRIAL ARTS; FABRICATED PLASTIC PARTS MANUFACTURED AND SOLD IN SEMI-FINISHED FORM; AND VULCANIZED FIBRE SHEETS, TUBES, RODS AND FABRICATED FORMS FOR GENERAL USE IN THE INDUSTRIAL ARTS