Steel Grating Material, Load & Surface Treatment
The hot dipped galvanized steel grating stair tread owns high corrosion resistance.
The steel grating technology demands contains many aspects, material, the steel grating loads and the steel grating surface treatment. To get high quality steel grating, we should allow the technology demands. We would discuss the technology further.
- The bearing bar. We use the GB/T 700 of the Q235-A & B to make the steel grating. Or we could use the other materials according to the clients needs.
- The bearing bars for the steel grating could be the hot rolled bearing bar, I type steel, or the hot & cold rolled steel belt that is cut vertically.
- The size tolerance range for the hot rolled bearing bar is like the flowing table.
- The section size of the I type steel should meet the needs of the following drawing and table.
|The standard size (mm)||The tolerance (mm)|
I type steel section drawing.
|I steel section width
|End thickness A
|Middle thickness B
|Middle width C
|End width d
|Section moment of resistance W
|Section moment of inertia I
|Standard size||Tolerance||Standard size||Tolerance||Standard size||Tolerance||Standard size||Tolerance|
The cross bar.
- The material for the cross bar is as the same as the bearing bar and it could meet the standard.
- The cross bar section. The cross bar use the twisted steel, round steel or the flat steel. The section should not be less than 20 mm2.
The end bar. The material of the end bar should be as the same as the bearing bar. The quality should meet the needs of the standard.
The steel grating loads.
- If there is cut out on the steel grating the left area of the steel grating should meet the design loads demands.
- The steel grating loads demands is from the design department and the clients. The clients could choose the steel grating type.
- The calculation for the steel grating loads, span and the deflection should according to the steel structure calculation principle.
The surface treatment for steel grating.
- The hot dipped galvanized coating.
The hot dipped galvanized coating starts after the wrapping. The steel grating weight after the galvanized coating should meet the GB/T 139112-2002 standard.
- The corrosion resistance coating.
The protection coating for the steel grating has the hot dipped galvanized. The other corrosion resistance coating and the paint could also protect the steel grating surface. The protection coating type is decided by the design department and the clients.