... >12 years factory 2>plain grating ,serrated,press lock 3>more kinds are OK ... 4>Strong structur Specifications of round bar grating paint steel grating12 years factoryplain grating ,serrated, press lockExport: Us,Eu,Uk ... ,AuStrong structure ,long life1.Steel grating standards:A) China: YB/T4001.1-2007B) USA: ANSI ... : untreated, painting or hot dip galvanizing. flat bar grating