TANTUNG
METALS AND ALLOYS THEREOF ADAPTED TO MAKE METAL WORKING AND CUTTING TOOLS, AND TO MAKE WEAR-RESISTING SURFACES, HAVING PARTICULAR REFERENCE TO REFRACTORY METALS SUCH AS TANTALUM, COLUMBIUM, MOLYBDENUM, OR TUNGSTEN, AND ALLOYS THEREOF
Cancelled · November 1, 1939 · 71425034 ·