Tungsten, molybdenum, tantalum a me ka niobium i nui mea no ka maunakea a me ka hoomalu ana i na hana ma muli o kā lākou i ka waiwai: ka mea kiʻekiʻe-mahana kumupaʻa, nuʻa a me tensile ikaika, kā lākou maikaʻi nā machinability, a me ka pāhawewe hoomalu.