Carbon karfe rukuni ne na karfe tare da carbon a matsayin babban sinadari mai haɗawa da ƙaramin adadin sauran abubuwan sinadarai. Bisa ga abun ciki na carbon, simintin carbon karfe za a iya raba zuwa low carbon simintin karfe, matsakaici carbon simintin karfe da babban carbon simintin karfe. Abubuwan da ke cikin carbon ɗin ƙananan ƙarfe na simintin carbon bai wuce 0.25% ba, yayin da abun cikin carbon na matsakaicin simintin carbon karfe yana tsakanin 0.25% da 0.60%, kuma abun cikin carbon na babban simintin ƙarfe yana tsakanin 0.60% da 3.0%. Ƙarfi da taurin simintin ƙarfe na simintin ƙarfe yana ƙaruwa tare da karuwar abun cikin carbon.Cast carbon karfe yana da wadannan abũbuwan amfãni: ƙananan samar da farashin, mafi girma ƙarfi, mafi kyau tauri da kuma mafi girma roba. Ana iya amfani da simintin ƙarfe na simintin ƙarfe don kera sassan da ke ɗaukar kaya masu nauyi, kamar madaidaicin injin mirgine ƙarfe da sansanonin latsawa na ruwa a cikin injuna masu nauyi. Hakanan za'a iya amfani da shi don kera sassan da ke ƙarƙashin manyan ƙarfi da tasiri, kamar ƙafafu, ma'aurata, bolsters da firam ɗin gefe akan motocin jirgin ƙasa.