Tungsten Ring TUR31 a comfort fit tungsten ring with a shank size of 6mm. Tungsten carbide is a very hard, dense metal, twice as hard as steel. It always remains polished and is scratch resistant. Available from ring size 5 to 15. Rings are supplied in a black ring box with a white pad. Ring boxes are supplied in a sleeve, labeled with product number and suggested retail price, for your convenience.