Ƙarfin wutar lantarki na jan ƙarfe shine na biyu kawai na azurfa, ya kai 58.5 MS/m (miliyan Siemens a kowace mita) a digiri 20. Wannan sifa ta sanya ta zama zaɓin da aka fi so don mafi girma -ƙarfin wutar lantarki da girma{4}} al'amuran yau da kullun. Sabanin haka, ƙarfin lantarki na aluminum yana kusan 37.7 MS/m, wanda shine kawai 64.5% na na jan karfe. Ƙarƙashin wannan yanki - yanki ɗaya, ƙarfin ɗaukar motocin bus na aluminum yana da kusan 30% ƙasa da na tagulla. Don cimma daidaiton wutar lantarki iri ɗaya, ana buƙatar ƙara girman yanki na bus ɗin aluminum, yana haifar da ƙara girma da nauyi.
Koyaya, girman girman jan ƙarfe (8.96g/cm³) shima yana kawo koma baya. A cikin yanayi inda ake buƙatar ƙira mai sauƙi, sandunan aluminum (tare da girman 2.7g/cm³) har yanzu suna iya cimma jimlar nauyi fiye da na sandunan jan ƙarfe ta hanyar haɓaka giciyensu{3}} yanki. Misali, a cikin haɗin fakitin baturi don sabbin motocin makamashi, sandunan aluminium ana karɓar ko'ina saboda fa'idar nauyinsu, kodayake ana buƙatar jiyya na iskar shaka don haɓaka juriyar lalata su.
