Sumul karfe bututu ga mai fatattaka, sered kamar yadda fumace bututu, zafi musayar bututu da kuma
bututun mai a masana'antar mai da matatun mai.Mahimman ingancin carbon tsarin karfe maki 20g,
20mng da 25mng; Alloy tsarin karfe maki: 15mog, 20mog, 12crmog, 15CrMoG, 12Cr2MoG, 12CrMoVG, da dai sauransu