1. Nias-(rolling)-stretching-(annealing)-cov khoom tiav.
2. Nruam casting (sab sauv, kab rov tav los yog lub log, crawler, impregnation) - (rolling) - stretching - (annealing) - xov - khoom tiav
3. Nruam extrusion-stretching-(annealing)-cov khoom tiav-cov khoom tiav.
