Sab hauv ntawm lub qhov rooj hluav taws steel yog ntim nrog ib puag ncig-phooj ywg hluav taws kub retardant thiab cov khoom siv rwb thaiv tsev kub, uas yog zoo li cov khoom siv ntawm cov concave thiab convex ntawm lub qhov rooj thiab nias los ntawm ib puag ncig-phooj ywg nplaum. Nyob rau hauv lub steel hluav taws qhov rooj kiv cua thiab lub qhov rooj thav duab ua ke thiab hluav taws kub iav nyob ib ncig ntawm, yog ua los ntawm cov hluav taws foob ua, thiaj li hais tias cov hluav taws kev ua tau zoo heev zog.