• awọn ohun amorindun irin pataki ti o gbona ati awọn ọpa yika (irin irinṣẹ iṣẹ gbona, irin ṣiṣu ṣiṣu, bbl)• annealed / normalized & tempered / quenched & tempered ifijiṣẹ ipo• dudu / milled / ti o ni inira yipada dada