Heavy Duty Load Tables
Load and span data for heavy-duty welded bar grating. For industrial platforms and high-load applications.
Design basis
- Material: carbon steel, ASTM A1011 / A36-equivalent, Fy = 36 ksi (250 MPa).
- Pattern: welded 19-W-2 (bearing bars 1-3/16" / 30 mm on center; cross bars 2" / 50 mm on center) for highest capacity, or 19-W-4 with heavier bearing bars.
- Bearing bar thickness: 1/4" (6 mm).
- Allowable bending stress: 0.66 Fy = 24 ksi (165 MPa) per AISC ASD.
- Deflection reference: L/240 for vehicle traffic, L/360 for forklifts and point loads.
- Support condition: simple span, two ends, banded panel with reinforced edge band where required.
Allowable uniform load — welded 19-W-2, 1/4" bearing bar
| Bearing bar depth | 36" (915 mm) | 48" (1220 mm) | 60" (1525 mm) | 72" (1830 mm) | 84" (2135 mm) | 96" (2440 mm) |
|---|---|---|---|---|---|---|
| 2" × 1/4" | 820 | 460 | 295 | 205 | 150 | 115 |
| 2-1/4" × 1/4" | 1040 | 580 | 375 | 260 | 190 | 145 |
| 2-1/2" × 1/4" | 1280 | 720 | 460 | 320 | 235 | 180 |
| 3" × 1/4" | 1850 | 1040 | 665 | 460 | 340 | 260 |
| 3-1/2" × 1/4" | 2520 | 1415 | 905 | 630 | 460 | 355 |
| 4" × 1/4" | 3280 | 1850 | 1180 | 820 | 605 | 460 |
| 4" × 5/16" | 4100 | 2310 | 1480 | 1025 | 755 | 575 |
| 5" × 3/8" | 7690 | 4330 | 2770 | 1925 | 1415 | 1080 |
Values in pounds per square foot (psf). Bending-stress controlled, AISC ASD; verify deflection for long spans or vehicle loading. 1 psf ≈ 47.9 N/m².
Forklift / point-load guide
For forklifts, pallet jacks, and service vehicles, the governing load is almost always the wheel concentrated load, not uniform load. Typical equivalency for a 3,000 lb wheel on a 4" × 4" tire contact patch:
| Span | Recommended bar (1/4" thick) | Typical series |
|---|---|---|
| 36" (915 mm) | 2-1/2" × 1/4" | 19-W-2 |
| 48" (1220 mm) | 3" × 1/4" | 19-W-2 |
| 60" (1525 mm) | 3-1/2" × 1/4" | 19-W-2 |
| 72" (1830 mm) | 4" × 1/4" | 19-W-2 |
| 96" (2440 mm) | 4" × 5/16" or 5" × 3/8" | 19-W-2, reinforced band |
Typical applications
- Petrochemical and power-plant platforms with vehicle access.
- Mezzanines supporting pallet jacks and 3,000–5,000 lb forklifts.
- Offshore topsides, FPSO grating with H-rating requirements.
- Mine and aggregate screens, dump grates, trench covers over drive aisles.
FAQ — heavy-duty load tables
- What grating size should I use for a 48" span and 1,000 psf uniform load?
- A 3" × 1/4" bearing bar in welded 19-W-2 provides 1,040 psf allowable, just above 1,000 psf. Select 3-1/2" × 1/4" for comfortable deflection margin.
- Can heavy-duty grating handle forklift traffic?
- Yes, provided the wheel concentrated load is calculated explicitly. Typical 3,000 lb wheel loads at 48" clear span require 3" × 1/4" bearing bars; 5,000 lb class-3 forklifts require 3-1/2" to 4" bar with reinforced edge banding.
- How do I size grating for an H20 highway load (AASHTO)?
- An H20 truck equates to a 16,000 lb wheel load. This requires structural-plank or heavy welded grating 4" × 5/16" or deeper with short clear spans (typically ≤ 36"). Contact engineering for certified AASHTO-rated design.
- Do I need a banded or reinforced edge?
- Heavy-duty panels are always banded at the ends. Reinforced edge banding (a thicker outer bar) is recommended when wheel loads run parallel to panel edges or at panel joints.
- Does heavy galvanizing reduce load capacity?
- No. Hot-dip galvanizing per ASTM A123 adds approximately 80–100 µm of zinc and does not reduce bending strength. It slightly increases weight but within tolerance.
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