Guide
Steel Grating Sizes and Dimensions: What Each Number Means
By DONGFU GRATING Engineering Team · Published 2026-07-24 · Updated 2026-07-24
A usable grating specification separates panel fit from load-carrying geometry. State bearing bar depth and thickness, bearing bar spacing, cross-bar spacing, panel length and width, and the clear unsupported span. Mark the bearing bar direction on the drawing because those bars must bridge the supports. A panel can be longer than its clear span, and a spacing series such as 30/100 or 19-W-4 still does not state bearing bar depth and thickness. For replacement panels, add a measured sketch and close photographs of the grid, banding and supports. These inputs let the supplier confirm fit, weight and capacity without guessing.
The six dimensions to identify
| Item | What it controls | Example |
|---|---|---|
| Bearing bar depth × thickness | Section strength and panel weight | 30 × 3 mm |
| Bearing bar spacing | Bars per metre and opening width | 30 mm centres |
| Cross-bar spacing | Grid stability and opening length | 100 mm centres |
| Panel width | Dimension across bearing bars | State in mm or inches |
| Panel length | Dimension along bearing bars | State in mm or inches |
| Clear span | Unsupported distance between bearing edges | Show support lines |
Bearing direction is not optional
Parallel bearing bars carry the load and must bridge the supporting steel. Mark their direction with an arrow on each platform, walkway and trench layout.
Panel size and clear span are separate inputs. Show intermediate supports and the minimum bearing at each edge rather than assuming the outside panel dimension is the span.
Quotation dimension checklist
- Bearing bar depth and thickness
- Bearing bar and cross-bar spacing or named series
- Overall panel length and width
- Bearing bar direction and clear span
- Cut-outs, banding, removable edges and quantity by panel mark