Ko te waahanga kowhao he ahanoa o tetahi ahuahanga i hangaia ki te rino, ki te rino ranei, me tetahi mea he kaha me te pakari (pērā i te kirihou, te konumohe, te muka karaihe, me etahi atu) ma te hurihuri, te tangohanga, te whakarewa me nga mea pera. Kei roto ko te maitai koki, te rino hongere, te kurupae-I, te maitai tapawha, te kurupae-H, me etahi atu, he ahanoa o tetahi ahuahanga i mahia ki te rino, rino ranei, me tetahi mea he kaha me te pakari (pēnei i te kirihou, te konumohe, te muka karaihe. , etc.) by rolling, extrusion, casting and the like. Tae atu ki te koki maitai, te hongere maitai, I-beam, tapawha maitai, H-beam, etc.