... Standard: YB/T4001, ANSI/NAAMM-MBG531, BS4592, AS1657, JS31011.3 Grating Dimension Load Bearing Flat Bar sizeThickness≥3mm, depth ≥19mm19X3 ... .1.4 Grating type: flat bar: plain type, plain I type, serrated type, serrated I type; cross bar: round type and square twisted type.a.full range ... to cater to the variety of needs of customers.3. The high-tec techneque and equipment guarantee high quality ...