Ƙarfe mai zafi mai zafiAna yin kayayyakin ne daga slabs (wanda aka fi sani da ci gaba da yin simintin gyare-gyare) azaman albarkatun ƙasa, waɗanda ake dumama sannan a sanya su su zama tsiri ta hanyar jujjuyawar raka'a da gamawa.Zafin karfe mai zafi daga injin niƙa na ƙarshe na injin gamawa ana sanyaya shi zuwa saita zafin jiki ta hanyar kwararar laminar kuma ana mirgine shi cikin coils ɗin karfe ta coiler.