Bar grating designations: 19-W-4, 19-W-2, 15-SGI-2, 11-W-4 — bearing bar spacing, cross bar spacing, bearing bar sizes and weight per sq ft (NAAMM MBG 531 style)

sizes

58 in table

Notes

• Designation (the NAAMM Metal Bar Grating Manual, MBG 531, system as the distributors print it): the first number is the centre-to-centre spacing of the bearing bars in sixteenths of an inch (19 = 19/16 = 1-3/16 in), the letter(s) give the method (W welded steel, SG swaged rectangular bar, SGF swaged flush top, SGI swaged I-bar, R riveted steel, AR riveted aluminum), and the last number is the cross bar spacing in inches (usually 4 or 2); for riveted grating it is the rivet spacing (7, 3-1/2 or 5 in) and the first number is the space between bars, not centre to centre. So 19-W-4 is welded steel grating with bearing bars on 1-3/16 in centres and cross bars on 4 in centres. The MBG 531 manual itself was not read (the copies found are behind a login or a document site); the key above is as Direct Metals prints it and McNichols prints 'product spacing designation: 19-W-4 (19 = 1-3/16 in bearing bar spacing, W = welded, 4 = 4 in cross bar spacing)'.
• Bearing bar size is height (depth) × thickness, in inches. Standard-duty 19-W-4 steel uses bars from 3/4 × 1/8 to 2-1/2 × 3/16 in (McNichols series GW-75 to GW-250); heavy-duty welded bars run 1 × 1/4 to 6 × 1/2 in (Direct Metals; standard centres 15/16, 13/16, 1-3/8, 1-7/8 and 2-3/8 in). The clear space between bearing bars is the centre spacing minus the bar thickness (computed here): 1-3/16 − 3/16 = 1 in, which McNichols prints for GW-175. Open area also depends on the cross bars: McNichols prints 77% for 1-3/4 × 3/16 with 1/4 in twisted cross rods, a Sweets submittal sheet prints 83% for 1/8 in bars.
• Weights disagree between sellers and finishes: 1 × 3/16 in 19-W-4 is 7.5 lb per sq ft at McNichols and 7.30 (black) or 7.67 (galvanized) at Metals Depot; 2 × 3/16 is 14.1 and 13.90 / 14.20; 1-1/2 × 3/16 is 10.8 and 10.60 / 11.00. The 19-W-2 column in the McNichols sheet adds 0.9 lb per sq ft over 19-W-4 for every bar size (the extra cross bars). Metals Depot lists the bar as thickness × depth (1/8 × 1) where McNichols lists height × thickness (1 × 1/8); the page shows depth × thickness for both.
• Left out on purpose: span / load / deflection tables (they belong to the maker's published load tables for the exact series and finish), serrated-surface and ADA-specific details beyond the 11-W-4 stock rows, aluminum swaged and I-bar weights (the extract was garbled) and panel-width charts. No file: a grating panel's cross bar (twisted rod) and weld geometry are not published as numbers. McNichols publishes a spec sheet and CAD drawing PDF per grating item (the item page is linked, nothing is copied). Expanded steel and aluminum grating (also sold by pounds per sq ft): expanded-metal-standard-designations-swd-lwd.

Bar grating designations: 19-W-4, 19-W-2, 15-SGI-2, 11-W-4 — bearing… size chart

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

Xem scan

File coming

No downloadable true-size file yet: the published figures do not fix the whole shape, and Xem never guesses a number. A measured scan is planned; request it and it moves up.

Plain text: sheet.txt · JSON: /api/geometry?object=bar-grating-designations-19-w-4-naamm

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