Steel bar grating is an engineered metal grid flooring system composed of load-bearing bars and cross bars, joined through welding, press-locking, swaging, or riveting. It provides a high strength-to-weight ratio, open-area drainage, and slip-resistant surfaces for industrial and commercial applications. Heavy-duty steel bar grating specifically refers to panels with bearing bar thickness ≥6 mm and width ≥50 mm, engineered for loads exceeding 10 tons - making it suitable for forklift aisles, truck loading docks, power plant decks, mining walkways, and heavy machinery platforms.
As a professional steel structure manufacturer, GNEE offers all four grating manufacturing methods under one roof, with in-house hot-dip galvanizing and engineering support. Every panel is produced to international standards (ASTM, EN, BS, AS/NZS, JIS) and shipped with material test certificates.
Key Components of Heavy-duty Steel Bar Grating
Understanding the terminology of steel grating helps procurement teams and engineers communicate specifications precisely. The four core components are:
| Term | Definition | Range |
|---|---|---|
| Bearing Bar | The main load-carrying element running parallel to the span | Thickness: 3–12 mm • Depth: 25–200 mm |
| Cross Bar | Secures bearing bars at fixed intervals, provides lateral rigidity | Twisted square 5×5 / 6×6 / 8×8 mm • Round Ø6–12 mm |
| Bearing Bar Pitch | Center-to-center distance between adjacent bearing bars | 15/16" ~ 2-3/8" (24–60 mm) |
| Cross Bar Pitch | Center-to-center distance between cross bars | 2" or 4" (50 or 100 mm) standard |
| Span | Clear distance between supporting structures (the direction of bearing bars) | Typically 0.6 m to 2.0 m for heavy-duty |
| Open Area | Percentage of free open space for drainage and ventilation | 60% – 80% (varies with pitch) |
Grating designation system: The North American standard uses a three-part code (e.g., 19-W-4).
Technical Parameters & Specifications
The table below provides a complete parameter overview of GNEE's heavy-duty steel bar grating. Every parameter is customizable per project drawings. For load-specific engineering calculations, contact our technical team.
| Parameter | Specification |
|---|---|
| Product Name | Heavy Duty Steel Bar Gratin |
| Manufacturing Methods | Electro-Forge Welded (W) • Press-Locked (PL) • Swage-Locked (SL) • Riveted (R) |
| Material Grades | Carbon Steel: ASTM A36 / A992 • Q235 / Q345 • EN 10025 S235JR / S355JR • JIS SS400 / SM490A Stainless Steel: AISI 304 / 304L (general) • AISI 316 / 316L (marine / chemical) Aluminum: 6061-T6 (light-duty, corrosion-critical) |
| Bearing Bar Size | Thickness: 3, 4, 4.5, 5, 6, 8, 10, 12 mm (1/8"–1/2") Depth: 25, 30, 32, 35, 40, 45, 50, 60, 65, 70, 75, 80, 90, 100 mm (1"–4") I-Bar: 25×5×3, 30×5×3, 32×5×3, 40×5×3 mm etc. US standard: 1"×3/16", 1-1/4"×3/16", 1-1/2"×1/4", 1"×1/4", 2"×1/4" etc. |
| Bearing Bar Pitch | Metric: 12.5, 15, 20, 25, 30, 30.16, 31, 32.5, 34.3, 35, 40, 41.25, 60, 80 mm US standard: 19-W-4 (1-3/16"), 15-W-4 (15/16"), 11-W-4 (11/16"), 19-W-2, 15-W-2 |
| Cross Bar Type & Size | Twisted square: 5×5, 6×6, 8×8 mm • Round bar: Ø6, 7, 8, 9, 10, 12 mm |
| Cross Bar Pitch | 38.1, 40, 50, 60, 76, 80, 100, 101.6, 120, 135 mm • US standard: 2" / 4" |
| Surface Type | Plain (smooth) • Serrated (tooth / anti-slip) • I-Bar • Serrated I-Bar |
| Surface Treatment | Hot-Dip Galvanized (ASTM A123, zinc 70–100 μm) - default recommendation Powder Coated (RAL color, 60–80 μm) • Epoxy Painted (80–120 μm) • Mill Finish (uncoated) Stainless Steel: passivated / electrolytic polished |
| Load Capacity | Uniform load: 4,500 ~ 28,800 psf (215–1,378 kN/m²) Vehicular rating: AASHTO H-15, H-20, H-25 Deflection limit: L/240 (pedestrian) • L/400 (vehicular / precision equipment) |
| Open Area | 60% – 80% (varies with bearing bar pitch and cross bar pitch) |
| Panel Size | Standard: 5800×1000, 6000×1000, 6096×1000, 6400×1000 mm • 3'×20', 3'×24', 3'×30' Max: Width ≤1200 mm • Length ≤6000 mm • Cut-to-size available |
| Welding Process | Fully automatic electro-forge (resistance) welding - metallurgical fusion, no filler metal |
| Applicable Standards |
USA: ASTM A36 / A123 • ANSI/NAAMM MBG 531-88 Europe: EN 1090 • ISO 1461 (galvanizing) UK: BS 4592-1987 • Australia: AS/NZS 1657-1985 Germany: DIN 24537-1-2006 • Japan: JIS • China: YB/T 4001.1-2007 / GB/T 4001.1 |
| Custom Options | Cutouts & notches for pipes/columns • End banding (load banding) • Toe plates (100–132 mm) Stair tread nosing • Radial / fan-shaped / triangular panels • Special shapes per drawing |
| Packing | Steel-strap bundles with protective separators + waterproof wrap for sea freight; wooden pallet optional |
| MOQ & Lead Time | 100 m² (negotiable) • Standard: 10–15 days • Custom: 15–25 days • Expedited: 7–10 days |
Product Highlights of Our Heavy-duty Steel Bar Grating
Heavy-Duty Load Capacity - 4,500 to 28,800 psf
Bearing bars from 6 mm to 12 mm thick, engineered for AASHTO H-15 to H-25 vehicular traffic and heavy machinery loads.
Four Manufacturing Methods - Welded, Press-Locked, Swage-Locked, Riveted
Select the optimal construction method based on load requirements, budget, and application - from ultra-heavy welded panels to cost-effective press-locked grids.
Anti-Slip Safety - Serrated Surface Boosts 40-60% Slip Resistance
Serrated (tooth-shaped) bearing bars meet OSHA walking-working surface requirements for wet, oily, or inclined walkways.
Superior Corrosion Resistance - 40-50+ Years Outdoor Service Life
Hot-dip galvanized to ASTM A123 (zinc 70–100 μm). For marine or chemical environments, stainless steel 304/316 options extend service life to 25-40+ years.
High Open Area - 60-80% Free Drainage & Ventilation
The grid structure prevents water accumulation, ice formation, and debris buildup - reducing maintenance and corrosion risks.
Full Customization - Cut-to-Size, Cutouts, Special Shapes
Custom bearing bar sizes, spacing, cutouts for pipes and columns, end banding, toe plates, stair tread nosing, and radial/fan-shaped panels per your drawings.
Multi-Standard Compliance - Global Project Ready
Produced to ASTM, EN 1090, AS/NZS 1657, BS 4592, NAAMM MBG 531, JIS, and GB/T standards for international project compliance.
Low Total Cost of Ownership - Fastener-Free, Maintenance-Free
Electro-forge welded panels have no bolts to loosen under vibration. Hot-dip galvanizing eliminates repainting for decades.
Quality Control & Certifications
Every GNEE grating panel passes through a 6-step quality control process before shipment. Our in-house testing capabilities and third-party verification ensure that each batch meets the specified standard - critical for structural applications where failure is not an option.
| Step | Inspection Item | Method |
|---|---|---|
| 1 | Raw Material Chemistry & Dimensions | Spectrometer analysis + micrometer measurement |
| 2 | Bearing Bar Cutting Tolerance | Per NAAMM MBG 531 dimensional standards |
| 3 | Weld Joint Integrity | Visual + destructive sample test (shear strength ≥ base metal) |
| 4 | Galvanized Coating Thickness | Magnetic gauge per ASTM A123 (≥70 μm) |
| 5 | Load Capacity Sampling | Optional certified load test per project requirement |
| 6 | Final Visual & Packing Check | Surface defect scan + bundling integrity verification |
Certifications
ISO 9001:2015 Quality Management System.
CE Marking (EN 1090 Execution Class).
SGS / BV Third-Party Inspection (on request).
Material Test Certificates (MTC) per EN 10204 3.1/3.2.
Traceability
Heat number tracking from raw steel to finished panel.
Batch test certificates archived for 5+ years.
Production records linked to each shipment.
Material chemistry report available on request.
Installation Accessories & Fixing Methods
Proper installation ensures that grating panels perform to their full load capacity and remain secure under vibration, impact, and thermal cycling. Two primary fixing methods are used, each suited to different operational needs.
Fixing Method 1: Welding Fixation (Permanent)
Grating panels are welded directly to the supporting steel structure at bearing bar contact points. This method provides maximum rigidity and is ideal for permanent installations where panel removal is not required. After welding, the damaged galvanized layer must be repaired with zinc-rich paint to maintain corrosion protection.
Fixing Method 2: Clip Fastening (Removable)
Grating panels are secured using specialized clips that clamp the bearing bar to the support structure without welding. This allows panel removal for maintenance access, inspection, or cable routing. Clip installation can be performed by one person working from above - no drilling or on-site welding required.
Clip Types & Selection Guide
| Clip Type | Best For | Features |
|---|---|---|
| Saddle Clips | Standard grating panel fixation on steel beams | Most common type; single-person installation from above |
| G-Clips | Aluminum, stainless steel, and galvanized grating | Friction-based fastener; versatile across materials |
| Grate Fast Clips | Rapid installation projects | One-person operation; no drilling or welding needed |
| Weld Lugs | Heavy-duty panels requiring removability | Welded to support beam; panels can be lifted out |
| Z-Clips / R-Clips | Specialized or irregular installations | Multiple sizes available for any configuration |
Surface Treatment & Corrosion Protection
Surface treatment determines service life, maintenance cost, and total cost of ownership. Select the treatment based on your project environment:
| Environment | Recommended Treatment | Expected Life | Why |
|---|---|---|---|
| Inland / Dry | Hot-Dip Galvanized (ASTM A123, ≥70μm) | 40–50+ years | Zinc layer provides sufficient barrier protection in low-corrosion atmosphere |
| Coastal / Marine | Stainless Steel 316L (passivated) | 25–40+ years | 316L resists chloride corrosion; galvanizing alone insufficient in salt spray |
| Chemical Plant | Epoxy Painted (80–120μm) or Stainless 316L | 15–20 years | Chemical exposure accelerates zinc consumption; epoxy provides chemical resistance |
| Architectural / Decorative | Powder Coated (RAL color, 60–80μm) | 15–25 years | Aesthetic color matching with adequate corrosion protection |
| Indoor / Dry | Mill Finish (uncoated) | 5–10 years | Lowest cost; sufficient for controlled environments |
Serrated Surface - Anti-Slip Option
Serrated (tooth-shaped) bearing bars add 40–60% slip resistance compared to plain bars. They are strongly recommended for wet, oily, or inclined surfaces per OSHA 1910.22 (Walking-Working Surfaces) standards. All serrated surfaces are available in welded, press-locked, and swage-locked constructions.
For detailed galvanized grating specifications including the G-designation system (G253/30/100 etc.) and zinc coating standards, see our Galvanized Steel Grating page.
Industry Selection Guide - How to Choose the Right Grating?
Selecting the correct grating specification for your application ensures safety, longevity, and cost efficiency. The matrix below matches common industrial scenarios with recommended bearing bar sizes, surface types, and material treatments. For site-specific load calculations, contact our engineering team.
| Application | Recommended Spec | Surface | Material & Treatment | Load Class |
|---|---|---|---|---|
| Pedestrian Walkway & Platform | 25×3 / 30×3 mm, 30/100 pitch | Plain | Galvanized Carbon Steel | Light (≤4,500 psf) |
| Forklift Aisle | 40×5 mm, 30/50 pitch | Serrated | Galvanized Carbon Steel | Medium (≤12,600 psf) |
| Truck Loading Dock & Ramp | 50×5 ~ 75×6 mm, 30/50 pitch | Serrated | Galvanized Carbon Steel | Heavy (≤24,300 psf) |
| Airport / Heavy Vehicle Deck | 75×10 ~ 100×10 mm | Serrated | Galvanized Carbon Steel | Extra Heavy (≤28,800 psf) |
| Trench Cover & Drainage | 25×3 / 30×3 mm, 30/100 pitch | Plain | Galvanized Carbon Steel | Light-Medium |
| Chemical Plant & Marine Platform | 30×3 ~ 50×5 mm | Serrated | Stainless Steel 316L | Medium |
| Parking Garage Drainage | 40×5 / 50×5 mm | Plain | Galvanized Carbon Steel | Medium-Heavy |
| Stair Treads | 25×3 / 30×3 mm + nosing bar | Serrated + nosing | Galvanized Carbon Steel | Light |
| Power Plant Deck | 40×5 / 50×5 mm, 30/50 pitch | Plain or Serrated | Galvanized Carbon Steel | Medium-Heavy |
| Mining Walkway & Conveyor Access | 40×5 / 50×5 mm, 30/50 pitch | Serrated | Galvanized Carbon Steel | Medium-Heavy |
Not sure which spec you need? Send us your project drawings or tell us the traffic type (pedestrian/forklift/truck), span distance, and environment. Our engineers will recommend the optimal specification within 24 hours.
Packing & Shipping of Heavy-duty Steel Bar Grating
| Item | Details |
|---|---|
| Packing Method | Steel-strap bundling with protective separators + waterproof wrapping film; wooden pallet/crate available on request |
| Container Loading | 20GP: ~25–30 tons • 40HQ: ~25–28 tons (varies with grating spec) |
| Lead Time | Standard specs: 10–15 days • Custom specs: 15–25 days • Expedited: 7–10 days |
| Payment Terms | T/T (30% deposit, 70% before shipment) • L/C at sight |
FAQ:
What is steel bar grating used for?
Steel bar grating is primarily used for industrial flooring, walkways, platforms, trench covers, drainage gratings, stair treads, and safety barriers in power plants, factories, refineries, mining sites, airports, and infrastructure projects. Its open-grid design provides drainage, ventilation, and slip resistance while supporting heavy loads.
Can you custom cut and fabricate grating panels to drawings?
Yes. We provide full custom fabrication including non-standard bearing bar sizes (25×3 to 100×10 mm), custom spacing (bearing pitch 11–100 mm, cross pitch 30–120 mm), precision cutouts for pipes and equipment bases, end banding (load banding), toe plates (100–132 mm height), stair tread nosing, and special shapes (radial, fan-shaped, triangular) for circular tanks, manholes, and architectural features.