... 1.1 Material Q235 , or other equivalent material1.2 Grating Conformity Standard: YB/T4001, ANSI/NAAMM-MBG531, BS4592, AS1657, JS31011 ... flexible and controlled delivery to cater to the variety of needs of customers.3. The high-tec techneque and equipment guarantee ... high quality of gratings. Most of machine were imported from Japan, Germany,Switzerland,etc. ...