... platforms, trench gratings, and stair treads etc. Detailed Selling Lead Description steel grate, drainage grating is a NEW building material, it ... ,platform etc.Our main products are steel grating floor, trench cover, well cover, stair treads, fence etc. 1) Bearing Bar (Load ... . Commonly used for platforms, trench gratings, and stair treads etc. 6) Steel grating standards: A) China: YB/T4001-1998 B) USA ...