R04200 -Type 1, Reactor grade unalloyed niobium;
R04210 -Type 2, Komersyal nga grado unalloyed niobium;
R04251 -Type 3, Reactor grade niobium alloy nga adunay 1% zirconium;
R04261 -Type 4, Commercial grade niobium alloy nga adunay 1% zirconium;