Cov khoom siv sab hauv thiab sab nrauv rau kev ua lub qhov rooj steel hluav taws, txawm tias nws yog cov khoom ntim lossis cov hlau sab nrauv, raug xaiv. Cov yam ntxwv ntawm steel qhov rooj hluav taws tuaj yeem ua rau tib neeg xav tias muaj kev nyab xeeb dua thiab puas siab puas ntsws ntseeg steel qhov rooj ntau dua.