Cov yeeb nkab steel muaj hollow seem thiab nws qhov ntev yog ntau dua li txoj kab uas hla lossis ncig ntawm cov hlau. Raws li cov duab seem, nws tau muab faib ua voj voog, square, rectangular thiab tshwj xeeb-puab steel kav; Raws li cov khoom siv, nws tau muab faib ua carbon structural steel yeeb nkab, qis alloy steel yeeb nkab, alloy steel yeeb nkab thiab cov yeeb nkab steel yeeb nkab.