# 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)

> What does bar grating designation 19-W-4 mean, and what bearing bar sizes and weights does it come in?

- Category: Hardware › Materials & stock
- Kind: Standard part
- Basis: Direct Metals' designation key and size lists, McNichols' welded grating series GW-75 to GW-250, Metals Depot's stock list and two McNichols item pages; numbers only, load tables left out on purpose
- Page: https://xemstudio.com/objects/bar-grating-designations-19-w-4-naamm/ · JSON: https://xemstudio.com/api/geometry?object=bar-grating-designations-19-w-4-naamm · Plain text: https://xemstudio.com/objects/bar-grating-designations-19-w-4-naamm/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
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**Exact dimensions.** True size, with no tolerance added.

## 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.

## Sizes

| source | designation | bearing bar size (depth × thickness) | bearing bar spacing | clear space between bars (computed) | cross bar spacing / size | method / material | weight (lb per sq ft) | note |
|---|---|---|---|---|---|---|---|---|
| Direct Metals key | 19-W-4 | — | 19/16 in (1-3/16) centre to centre | — | 4 in centre to centre | welded steel | — | first number = bearing bar spacing in 1/16 in (30.16 mm centre to centre) |
| Direct Metals key | 19-W-2 | — | 19/16 in (1-3/16) centre to centre | — | 2 in centre to centre | welded steel | — | first number = bearing bar spacing in 1/16 in (30.16 mm centre to centre) |
| Direct Metals key | 15-SGI-2 | — | 15/16 in centre to centre | — | 2 in centre to centre | swaged I-bar | — | first number = bearing bar spacing in 1/16 in (23.81 mm centre to centre) |
| Direct Metals key | 38-W-4 (or 2) | — | 38/16 in (2-3/8) centre to centre | — | 4 in (or 2) centre to centre | welded steel | — | first number = bearing bar spacing in 1/16 in (60.32 mm centre to centre) |
| Direct Metals key | 30-W-4 (or 2) | — | 30/16 in (1-7/8) centre to centre | — | 4 in (or 2) centre to centre | welded steel | — | first number = bearing bar spacing in 1/16 in (47.62 mm centre to centre) |
| Direct Metals key | 22-W-4 (or 2) | — | 22/16 in (1-3/8) centre to centre | — | 4 in (or 2) centre to centre | welded steel | — | first number = bearing bar spacing in 1/16 in (34.92 mm centre to centre) |
| Direct Metals key | 11-SG-4 (or 2) | — | 11/16 in centre to centre | — | 4 in (or 2) centre to centre | swaged rectangular bar | — | first number = bearing bar spacing in 1/16 in (17.46 mm centre to centre) |
| Direct Metals key | 7-SG-4 (or 2) | — | 7/16 in centre to centre | — | 4 in (or 2) centre to centre | swaged rectangular bar | — | first number = bearing bar spacing in 1/16 in (11.11 mm centre to centre) |
| Direct Metals key | 18-R-7 (or 3-1/2) | — | 18/16 in = 1-1/8 in space between bars | — | 7 in (or 3-1/2) rivet spacing | riveted steel | — | riveted grating marking is the space between bars, not centre to centre |
| Direct Metals key | 37-R-5 | — | 37/16 in = 2-5/16 in space between bars | — | 5 in rivet spacing | riveted steel | — | riveted grating marking is the space between bars, not centre to centre |
| Direct Metals key | 12-R-7 (or 3-1/2) | — | 12/16 in = 3/4 in space between bars | — | 7 in (or 3-1/2) rivet spacing | riveted steel | — | riveted grating marking is the space between bars, not centre to centre |
| McNichols GW-75-A | 19-W-4 | 3/4 × 1/8 in | 1-3/16 in | 1.0625 in (27.0 mm) | 4 in | welded steel, carbon / galvanized (load-table sheet) | 4.1 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-75-A | 19-W-2 | 3/4 × 1/8 in | 1-3/16 in | 1.0625 in (27.0 mm) | 2 in | welded steel, carbon / galvanized (load-table sheet) | 5.0 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-75 | 19-W-4 | 3/4 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, carbon / galvanized (load-table sheet) | 5.8 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-75 | 19-W-2 | 3/4 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 2 in | welded steel, carbon / galvanized (load-table sheet) | 6.7 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-100-A | 19-W-4 | 1 × 1/8 in | 1-3/16 in | 1.0625 in (27.0 mm) | 4 in | welded steel, carbon / galvanized (load-table sheet) | 5.2 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-100-A | 19-W-2 | 1 × 1/8 in | 1-3/16 in | 1.0625 in (27.0 mm) | 2 in | welded steel, carbon / galvanized (load-table sheet) | 6.1 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-100 | 19-W-4 | 1 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, carbon / galvanized (load-table sheet) | 7.5 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-100 | 19-W-2 | 1 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 2 in | welded steel, carbon / galvanized (load-table sheet) | 8.4 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-125-A | 19-W-4 | 1-1/4 × 1/8 in | 1-3/16 in | 1.0625 in (27.0 mm) | 4 in | welded steel, carbon / galvanized (load-table sheet) | 6.3 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-125-A | 19-W-2 | 1-1/4 × 1/8 in | 1-3/16 in | 1.0625 in (27.0 mm) | 2 in | welded steel, carbon / galvanized (load-table sheet) | 7.2 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-125 | 19-W-4 | 1-1/4 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, carbon / galvanized (load-table sheet) | 9.1 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-125 | 19-W-2 | 1-1/4 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 2 in | welded steel, carbon / galvanized (load-table sheet) | 10.0 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-150-A | 19-W-4 | 1-1/2 × 1/8 in | 1-3/16 in | 1.0625 in (27.0 mm) | 4 in | welded steel, carbon / galvanized (load-table sheet) | 7.4 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-150-A | 19-W-2 | 1-1/2 × 1/8 in | 1-3/16 in | 1.0625 in (27.0 mm) | 2 in | welded steel, carbon / galvanized (load-table sheet) | 8.3 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-150 | 19-W-4 | 1-1/2 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, carbon / galvanized (load-table sheet) | 10.8 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-150 | 19-W-2 | 1-1/2 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 2 in | welded steel, carbon / galvanized (load-table sheet) | 11.7 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-175 | 19-W-4 | 1-3/4 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, carbon / galvanized (load-table sheet) | 12.5 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-175 | 19-W-2 | 1-3/4 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 2 in | welded steel, carbon / galvanized (load-table sheet) | 13.4 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-200 | 19-W-4 | 2 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, carbon / galvanized (load-table sheet) | 14.1 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-200 | 19-W-2 | 2 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 2 in | welded steel, carbon / galvanized (load-table sheet) | 15.0 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-225 | 19-W-4 | 2-1/4 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, carbon / galvanized (load-table sheet) | 15.8 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-225 | 19-W-2 | 2-1/4 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 2 in | welded steel, carbon / galvanized (load-table sheet) | 16.7 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-250 | 19-W-4 | 2-1/2 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, carbon / galvanized (load-table sheet) | 17.4 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| McNichols GW-250 | 19-W-2 | 2-1/2 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 2 in | welded steel, carbon / galvanized (load-table sheet) | 18.3 | bar depth × thickness; clear space = 1-3/16 − thickness (computed) |
| Metals Depot G1181 | 19-W-4 | 1 × 1/8 in | 1-3/16 in | 1.0625 in (27.0 mm) | 4 in | welded steel, black, smooth | 5.1 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G131634 | 19-W-4 | 3/4 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, black, smooth | 5.6 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G13161 | 19-W-4 | 1 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, black, smooth | 7.3 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G13161-G | 19-W-4 | 1 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, galvanized, smooth | 7.67 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G1316114 | 19-W-4 | 1-1/4 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, black, smooth | 8.9 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G1316114-G | 19-W-4 | 1-1/4 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, galvanized, smooth | 9.35 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G1316112 | 19-W-4 | 1-1/2 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, black, smooth | 10.6 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G1316112-G | 19-W-4 | 1-1/2 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, galvanized, smooth | 11.0 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G1316134S | 19-W-4 | 1-3/4 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, black, serrated | 12.2 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G13162 | 19-W-4 | 2 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, black, smooth | 13.9 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G13162-G | 19-W-4 | 2 × 3/16 in | 1-3/16 in | 1.0000 in (25.4 mm) | 4 in | welded steel, galvanized, smooth | 14.2 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G114112 | 19-W-4 | 1-1/2 × 1/4 in | 1-3/16 in | 0.9375 in (23.8 mm) | 4 in | welded steel, black, smooth, heavy duty | 13.51 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G1142 | 19-W-4 | 2 × 1/4 in | 1-3/16 in | 0.9375 in (23.8 mm) | 4 in | welded steel, black, smooth, heavy duty | 18.7 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G114212 | 19-W-4 | 2-1/2 × 1/4 in | 1-3/16 in | 0.9375 in (23.8 mm) | 4 in | welded steel, black, smooth, heavy duty | 23.09 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G1143 | 19-W-4 | 3 × 1/4 in | 1-3/16 in | 0.9375 in (23.8 mm) | 4 in | welded steel, black, smooth, heavy duty | 27.5 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G13161-11W4-P | 11-W-4 | 1 × 3/16 in | 11/16 in | 0.5000 in (12.7 mm) | 4 in | welded steel, black, smooth, ADA | 11.9 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G1316114-11W4P | 11-W-4 | 1-1/4 × 3/16 in | 11/16 in | 0.5000 in (12.7 mm) | 4 in | welded steel, black, smooth, ADA | 14.7 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| Metals Depot G1316112-11W4P | 11-W-4 | 1-1/2 × 3/16 in | 11/16 in | 0.5000 in (12.7 mm) | 4 in | welded steel, black, smooth, ADA | 17.5 | bar listed as thickness × depth by the seller; shown here depth × thickness |
| McNichols item 6607310122 | 19-W-4 (series GW-175) | 1-3/4 × 3/16 in | 1-3/16 in, 1 in clear | 1.0000 in (25.4 mm), printed | 4 in; 1/4 in square twisted rod | carbon steel, hot rolled | 12.50 | 77% open area, 10.1053 bars per foot of width (printed) |
| Sweets submittal sheet | 19-W-4 | 1/8 in thick | — | — | 4 in | welded | — | 83% open area (printed, bar 1/8 in thick) |
| McNichols item 67153163 (SAFE-T-GRID) | 19-S-4 (series TB-940-150) | T-bar 1-1/2 in high, 0.940 in top flange, web 1/8 in, bottom flange 1/4 in | 1-3/16 in | — | 4 in; 3/8 in square rod | aluminum 6063-T6, swage-locked, grooved | 4.30 | 21% open area |
| Direct Metals stock list | 19-W-4 light duty stainless | 1 × 3/16, 1-1/4 × 3/16, 1-1/2 × 3/16 in | 1-3/16 in | — | 4 in | stainless 304 | — | stocked sizes |
| Direct Metals stock list | 7-TW-4 (TiteWeld) | 3/4 to 2-1/2 in high × 3/16 in in 1/4 in steps | 7/16 in | — | 4 in | welded steel | 13.73 (3/4) to 44.31 (2-1/2) | 8 sizes; weights listed in order in a garbled extract, first and last only given |

## Where the files are

- Direct Metals (grating catalogue, hosted on Simplebooklet): [Glossary of bar grating: designation key (bearing bar spacing in 1/16 in, method letter, cross bar spacing) and bar grating tables: bearing bar sizes, panel widths, weights](https://simplebooklet.com/glossaryofbargrating?textonly=1) — web — Distributor catalogue; numbers only
- Direct Metals (grating catalogue, hosted on Simplebooklet): [Entire bar grating section: designations, bearing bar sizes by type, light and heavy duty welded steel, stainless, aluminum (the text extraction is garbled in places; only clearly legible values used)](https://simplebooklet.com/entirebargratingsection?textonly=1) — web — Distributor catalogue; numbers only
- McNichols: [Standard-duty welded bar grating, series GW-75 to GW-250: bearing bar height × thickness and weight in 19-W-4 and 19-W-2 (load table PDF; loads not copied)](https://assets.mcnichols.com/content/dam/mcnichols/resources/PDF/LT-SDW-GW-GW2-CS-GV.pdf) — web — Maker sheet; numbers only
- McNichols: [Welded bar grating item 6607310122 (GW-175, 19-W-4): bearing bar 1-3/4 × 3/16, cross bar 1/4 square twisted rod, 77% open, 12.50 lb per sq ft; spec sheet and CAD drawing PDFs](https://www.mcnichols.com/bar-grating/welded/carbon-steel-cs-66073101) — PDF, DWG — Maker site terms (drawings per item; DWG may need a login) (verify at link)
- McNichols: [SAFE-T-GRID aluminum swage-locked T-bar grating TB-940-150 (19-S-4): 1-1/2 in T-bar, 3/8 in square cross bar, 4.30 lb per sq ft, 21% open area](https://www.mcnichols.com/bar-grating/swage-locked/aluminum-al-67153163) — web — Maker page; numbers only
- Metals Depot: [Steel bar grating: stock numbers with bearing bar size, 19W4 / 11W4 spacing, 4 in cross bars, weight lb per sq ft, smooth / serrated, black / galvanized](https://www.metalsdepot.com/steel-products/steel-bar-grating) — web — Distributor page; numbers only
- Sweets (manufacturer submittal sheet, maker not named in the text read): [Welded bar grating 19-W-4 submittal: 1/8 in bearing bar thickness, 83% open area, cross bars 4 in on centre](https://sweets.construction.com/swts_content_files/1097/484577.pdf) — web — Submittal sheet; numbers only

## Questions

**What does 19-W-4 grating mean?**

Welded steel grating with bearing bars on 19/16 in = 1-3/16 in centres and cross bars on 4 in centres (Direct Metals; McNichols).

**What is the difference between 19-W-4 and 19-W-2?**

Same bearing bar spacing, but cross bars every 2 in instead of 4 in. McNichols' sheet adds 0.9 lb per sq ft for 19-W-2 at every bar size, for example 7.5 against 8.4 for 1 × 3/16.

**What size are the bearing bars of 19-W-4 grating?**

Standard-duty stock runs 3/4 × 1/8 to 2-1/2 × 3/16 in (McNichols GW-75 to GW-250); Metals Depot also lists 1/4 in bars from 1-1/2 to 3 in high.

**How much does 1 × 3/16 19-W-4 grating weigh?**

7.5 lb per sq ft (McNichols GW-100); 7.30 black and 7.67 galvanized (Metals Depot).

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