1. The weight of a steel grating will increase after enclosure and hot dip galvanizing treatment on its surface.Its weight will increase 12% to 16% for the general industrial platform.
    
2. In case drawings are not available and processing shall have to be made according to dimension provided by customers, the area shall mean that the quantity of steel grating actually paid is multiplied by the sum of length and width, including tapping and notching part.
    
3. In case we offer drawings and design the layout plan of steel grating for customers,the area shall be calculated based on total external dimension in drawings, containing tapping and notching part.
    
4. For special shaped gratings, the final grating quantities shall be based on the total gross area calculated to length (L) times width(W) of all the pieces furnished, with no deduction made for cutouts.

See the following sketches for some typical cases.