Tsarin farantin karfe:
Ana amfani da shi musamman don kera sassan karfe, gadoji, jiragen ruwa da ababen hawa.
Weathering karfe farantin:
Ƙarin abubuwa na musamman (P, Cu, C, da dai sauransu) yana da kyakkyawan juriya na lalata da kuma juriya na yanayi, kuma ana amfani dashi a cikin samar da kwantena, motoci na musamman, da kuma gine-ginen gine-gine.
Farantin karfe na musamman mai zafi:
Carbon karfe, gami karfe da kayan aiki karfe ga general inji tsarin da ake amfani a samar da daban-daban inji sassa bayan zafi magani injiniya.