A NAAMM grating specification starts with the appropriate publication and the project’s design conditions. “NAAMM grating” alone does not state the material, panel geometry, loading or documents needed for approval.
Choose the relevant NAAMM publication
- MBG 531-24, Metal Bar Grating Manual: NAAMM describes this as technical data, specifications and recommended practices for steel, stainless steel and aluminum gratings, with load tables and installation details. See the official MBG 531 publication page.
- MBG 532-24, Heavy Duty Metal Bar Grating Manual: covers heavy-duty carbon and stainless steel bar grating, including fabrication, dimensional information, load tables and guide specifications.
- MBG 534-24, Metal Bar Grating Engineering Design Manual: is the engineering design publication.
- MBG 535-25, Metal Bar Grating Code of Standard Practice: is a separate standard-practice publication. The NAAMM publications directory lists these documents and downloads.
Identify the document and edition required by the contract. A publication title or year on a website should not silently replace the edition already specified for a project.
Prepare the panel design information
Give the reviewer a panel schedule showing bearing bar depth, thickness, spacing and direction; cross bar spacing; material; surface type; finished panel dimensions; and panel marks. Show the supports and clear span on the drawing. Opening dimensions and panel dimensions should be labelled separately.
State the design loads and deflection criterion. Identify concentrated loads, carts or vehicle loading rather than describing every location as a general walkway. For unusual openings, interrupted bearing bars or special support arrangements, flag the detail for design review instead of assuming a standard table applies unchanged.
Review the load-table or calculation submission
- Record the publication or calculation reference and the units used.
- Match the proposed bar geometry and material to the drawing.
- Check that the span, support arrangement and load case match the project.
- Record the acceptance criterion and the reviewer responsible for approval.
- Keep the accepted drawing revision with the calculation or table reference.
This review record makes assumptions visible. It is more useful than a standalone statement that the grating “meets NAAMM,” and it helps prevent a table for one configuration being carried into a different panel layout.
Complete the purchase and installation scope
After the design information is agreed, list the finish, cut-outs, banding, toe plates, fixing accessories, panel identification and required inspection documents. Show which items are supplied with the grating and which are provided by others. Separate these scope checks from the structural review.
NAAMM specification questions
Is NAAMM a steel material grade?
No. Identify the actual material and applicable material specification separately from the NAAMM publication used for the grating requirements.
Can I select grating using a load table alone?
The selected entry must match the actual panel and project conditions. If the drawing changes the span, supports or bearing bars, ask the responsible reviewer to check the selection again.
For material and coating references, read the ASTM steel grating guide. Return to the standards overview or send the project specification with your enquiry.
