Cov qhov rooj hlau yog dav siv nyob rau hauv ntau yam teb vim lawv qhov zoo xws li lub zog siab, durability, suab thiab cua sov rwb thaiv tsev, hluav taws kub tsis kam, thiab tiv thaiv- cov khoom tub sab:
Tsev: Hlau nkag qhov rooj thiab qhov rooj ruaj ntseg yog dav siv hauv tsev, muab kev ruaj ntseg thiab zoo nkauj rov hais dua.
Chaw Pej Xeem: Cov chaw xws li tsev kawm ntawv, tsev kho mob, tsev qiv ntawv, tshav dav hlau, chaw nres tsheb ciav hlau, thiab chaw nres tsheb subway muaj qhov xav tau ntau dua rau kev nyab xeeb ntawm lub qhov rooj thiab kev ua haujlwm. Lub zog siab thiab ua haujlwm ntev ntawm cov qhov rooj steel tuaj yeem tiv taus qhov cuam tshuam sab nraud, thaum tseem muab lub suab zoo thiab rwb thaiv tsev kub, tsim kom muaj ib puag ncig zoo rau cov neeg siv.
Cov Vaj Tsev Ua Lag Luam: Rau cov kev nkag loj lossis cov chaw loj hauv cov khw muag khoom, cov chaw ua yeeb yam, cov tsev khaws ntaub ntawv tshawb fawb, thiab cov chaw sib tham hauv nroog, ntxiv rau - cov qhov rooj hlau loj tuaj yeem txhim kho tag nrho cov duab ntawm lub tsev thiab ua tau raws li cov kev xav tau ntawm cov neeg thiab cov khoom lag luam.
Cov Tsev Tsim Kho: Cov chaw tsim khoom loj, cov tsev khaws khoom, thiab cov chaw thauj khoom xav tau ntxiv - cov qhov rooj steel loj kom tau raws li cov kev xav tau ntawm cov khoom loj thiab cov khoom nkag thiab tawm, thaum tseem muab kev tiv thaiv hluav taws thiab tiv thaiv - kev nyab xeeb tub sab.
Qhov chaw tshwj xeeb: Rau cov chaw uas muaj kev nyab xeeb thiab kev nyab xeeb, xws li chaw nres tsheb, chav faib hluav taws xob, thiab cov chaw khaws ntaub ntawv, ntxiv - cov qhov rooj hlau loj tuaj yeem muab ntau yam kev tiv thaiv xws li hluav taws kub nyhiab, tiv thaiv dej, tiv thaiv - tub sab, thiab hluav taws xob tiv thaiv kev cuam tshuam.
