Tianjin Rainbow Karfe yana kera bututu mai murabba'i wanda wani nau'in karfe ne mai tsayi mai tsayi tare da sashe mara tushe kuma babu dunkule a kusa da shi.Yana da asquare tubekafa ta hanyar extrusion na bututu maras kyau ta bangarori hudu na mutu.Bututun murabba'i yana da sashin rami kuma ana amfani da shi sosai azaman bututu don isar da ruwa.An fi amfani dashi a cikin sufuri na ruwa, goyon bayan hydraulic, tsarin injiniya, matsakaici da ƙananan matsa lamba, babban bututun tukunyar jirgi, bututun musayar zafi, gas, mai da sauran masana'antu.Yana da ƙarfi fiye da walda kuma ba crack.Hot birgima karfe shambura ana kerarre ta wucewa sheet karfe ta rollers cimma takamaiman jiki girma.Samfurin da aka gama yana da ƙaƙƙarfan ƙarewa tare da sasanninta radiused, kuma ko dai wani welded ko gini mara kyau.Kera zafi mai birgima murabba'in bututun ƙarfe ya ƙunshi mirgina karfe a yanayin zafi da ya wuce Digiri 1,000.