Hot birgima (extrusion sumul karfe bututu): zagaye tube → dumama → perforation → → mirgina uku-bidi, mirgina ko extrusion → ware → girman (ko rage) → sanyaya → daidaitawa na'ura mai aiki da karfin ruwa gwajin (orflaw) → tag → ajiya.

Mirgina bututu na albarkatun kasa bututu ne mai zagaye, bututun embryos suna bi ta na'urar yankan don yanke ci gaban digiri kamar mita 1, kuma ana aika ta hanyar dumama tanderu mai bel.Ana ciyar da Billet a cikin tanderun dumama, zafin jiki yana kusan digiri 1200 ma'aunin Celsius.Fuel don hydrogen ko acetylene.Matsakaicin zafin wutar tanderu yana da mahimmanci don sanya bututun iska zagaye, bayan sakin bugun bugun.waxanda gabaɗaya suka fi kowa naushi mai naushi mai naushi wannan naushi, ingantaccen samarwa, ingancin samfur, faɗaɗa ƙarar ƙura, sanye da ƙarfe iri-iri.Bayan huɗawa, bututun zagaye ya kasance mai jujjuyawar giciye mai birgima, birgima ko extrusion.Bayan extrusion kashe bututu sizing.Girman niƙa ta hanyar jujjuyawar mazugi mai sauri a cikin bututun Billet don samar da bututun ƙarfe.An ƙaddara diamita na bututun ƙarfe na ciki ta tsawon tsayin diamita na waje na rawar sojan niƙa.Bayan girman, bututun ƙarfe don shigar da hasumiya mai sanyaya ta hanyar sanyayawar ruwa, bututun ƙarfe bayan sanyaya, dole ne a daidaita.An aika ta bututun isar da sako ta hanyar daidaita injin gano ƙarfe (ko gwajin hydrostatic) don gudanar da aibi na ciki.Abubuwan da ke cikin bututun ƙarfe kamar fashe, kumfa za a gano.Binciken ingancin bututun ƙarfe amma kuma ta hanyar zaɓi mai tsauri.Karfe bututu na Ingancin Kulawa, dubawa, yi amfani da fenti mai feshi akan lamba, girman, tsari na samarwa.Ta hanyar motar kebul da ke rataye a cikin sito.