The carbon karfe sumul karfe bututu da aka yi da wani dukan yanki na karfe kuma ba shi da wani kabu a kan surface. Bisa ga samar da hanya, sumul bututu an raba su zuwa zafi tube, sanyi birgima bututu, sanyi-ja bututu, extruded bututu, bututu. jacking da sauransu.An fi amfani da bututun ƙarfe maras sumul a matsayin bututun hakowa don ilimin kimiyyar man fetur, fasa bututu don masana'antar petrochemical, bututun tukunyar jirgi, bututu masu ɗaukar nauyi da ingantaccen bututun ƙarfe na ƙarfe don motoci, tarakta da jirgin sama.