Ọkpụkpụ nchara gburugburu bụ ụdị ọkpọkọ nwere akụkụ okirikiri, nke nwere mpaghara ngwa ngwa.Ọ bụghị naanị na ọ nwere njirimara pụrụ iche, kamakwa ọ nwere atụmanya dị ukwuu nke ngwa ngwa.
Usoro: Ndị ọzọ, Hot Rolled, Cold Rolled, ERW, High-frequency welded, Extruded