Awọn ohun elo irin ti pin si awọn ẹka mẹfa:

(1) P-irin

(2) M- irin alagbara, irin

(3) K-simẹnti irin

(4) N-ti kii-ferrous awọn irin

(5) S- ooru sooro alloy

(6) H-lile irin