Karfe da aka saba amfani da su don yin kayan aikin gini ana kashe su da ƙarfe mai zafi, ƙarfe mai tauri, carburized da taurin ƙarfe da ƙarfe nitrided. Ƙarfin simintin ƙarfe na simintin ƙarfe yana ɗan ƙasa da na jabun kayan ƙarfe na ƙarfe, kuma galibi ana amfani dashi don manyan gears, baƙin ƙarfe simintin ƙarfe yana da ƙarancin kayan aikin injiniya kuma ana iya amfani dashi a cikin watsa kayan buɗaɗɗen kaya, ductile baƙin ƙarfe na iya partially. maye gurbin karfe don yin gears.
A nan gaba, kayan aikin gine-gine suna tasowa a cikin jagorancin nauyi mai nauyi, babban sauri, babban madaidaici da ingantaccen aiki, kuma suna ƙoƙari su zama ƙananan girman, haske a nauyi, tsawon rayuwa da amincin tattalin arziki.