Galvanized Steel Grating
Hot-dip galvanized carbon steel grating (Q235B/A36) per ASTM A123 — 70–85 µm zinc layer, 1,000 h salt-spray resistance, 40–70 years to first maintenance in most US environments.
Get a Quote Download CatalogCoating thickness & weight by section
Screenshot-ready. Every dimension below is a standard tooling size — custom spacings are cut to your drawing at no extra mold cost.
| Bearing bar (mm) | Steel weight (kg/m²) | Zinc pickup (kg/m²) | Total galv. weight | Zinc thickness |
|---|---|---|---|---|
| 25×3 / 30/100 | 22.4 | 1.1 | 23.5 | 72–80 µm |
| 32×3 / 30/100 | 26.5 | 1.2 | 27.7 | 72–82 µm |
| 32×5 / 30/100 | 42.8 | 1.5 | 44.3 | 75–85 µm |
| 40×5 / 40/100 | 39.6 | 1.4 | 41.0 | 75–85 µm |
| 50×5 / 50/100 | 34.8 | 1.3 | 36.1 | 75–85 µm |
Zinc thickness measured per ASTM A123 magnetic gauge on bearing bar faces and edges after venting/drainage holes are plugged per ASTM A385 practice.
Choose your construction and material
Each family has its own load table, finish options and lead time.
Galvanized Walkway Panels
30/100 and 40/100 stock pitches, cut to size.
View series → Product FamilyGalvanized Stair Treads
Serrated surface treads, OSHA compliant.
View series → Product FamilyGalvanized Trench Covers
EN 1433 A15–D400 with frames.
View series → Product FamilyPainted / Mill Finish
For indoor dry service — saves the zinc cost.
View series →Four material systems, one factory
Zinc thickness is measured per ASTM A123 (70–85 µm), salt-spray tested to 1,000 h. Stainless is pickled and passivated; FRP resin is matched to your chemical media.
| Material | Specification | Best For | QC Note |
|---|---|---|---|
| Carbon Steel, Hot-Dip Galvanized | Q235B / A36, zinc 70–85 µm per ASTM A123 | Walkways, platforms, trench covers, stair treads — the default choice | 1,000 h neutral salt-spray test before white rust |
| Stainless Steel 304 / 316L | AISI 304 (indoor / general chemical), 316L (marine / chloride) | Food processing, pharma, offshore, chemical plants | Passivated and pickled finish, 316L for >3% chloride media |
| Aluminum 6061-T6 | Mill or anodized finish, riveted or press-locked construction | Weight-critical platforms, water treatment, architectural meshes | ≈ 1/3 the weight of steel at comparable spans — cannot be hot-dip galvanized |
| FRP / Fiberglass (GRP) | Molded (isophthalic / vinyl ester) or pultruded profiles | Electrolytic areas, sewage plants, coastal platforms | Non-conductive, non-sparking, corrosion-free alternative to metal |
Coating life to first maintenance (per ASTM A123 practice + ISO 14713)
Values calculated to NAAMM MBG 531 with deflection limited to L/200. Need a stamped calculation sheet for your span? Ask in the quote form.
| Environment | Zinc loss (µm/year) | 70 µm coating life | 85 µm coating life |
|---|---|---|---|
| Rural / dry inland | 0.1–0.3 | 70+ years | 70+ years |
| Urban / suburban US | 0.3–0.6 | 40–70 years | 55–70 years |
| Industrial (SO₂, exhaust) | 0.8–1.5 | 20–30 years | 25–35 years |
| Coastal (salt fog, <1 km) | 1.0–2.0 | 15–25 years | 20–30 years |
| Wet/dry splash zones | 1.5–3.0 | 10–15 years | 12–18 years |
Zinc loss rates per ISO 14713-2 corrosivity categories C2–C5. Rust appearing earlier than this usually traces to cut edges not re-galvanized or faying surfaces under clips.
Where galvanized steel grating works hardest
Reference projects available per industry on request.
Outdoor walkways & catwalks
The default outdoor industrial floor — zero paint maintenance.
Trench & drainage covers
Class A15–D400 with matching galvanized frames.
Stair treads & fire escapes
Serrated galvanized treads for rain, snow and ice.
Loading docks & yards
40×5 / 50×5 heavy sections around truck traffic.
Barns & irrigation channels
Cost-effective corrosion protection in wet ag service.
Cooling towers & plants
Hot-dip beats paint near spray and humidity cycles.
Send a drawing, receive a finished panel
Upload DXF or DWG with your RFQ — we return a dimensioned shop drawing for approval within 24 hours. No approval, no production.
In-house fabrication
- Cut-to-size from DXF / DWG drawings — band saw and plasma, ±2 mm tolerance
- Notching and cutouts for pipes, cable trays and manholes in any shape
- Banding (closed ends) in flat bar or checkered plate, toe plates to EN ISO 14122-3
- Curved and radial panels for tanks, towers and architectural projects
- Stair tread fabrication with welded or bolted carriers, nosing options
- Pre-assembly of clips, anchors and support steel into kit form for site speed
Everything is auditable
Third-party inspection (SGS/BV/TÜV) welcome at any stage. MTC per EN 10204 3.1 ships with every order by default.
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ASTM A36 — carbon structural steel bar and plate
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ASTM A123 — hot-dip galvanizing, 70–85 µm zinc coating on bearing bars
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ASTM A1011 / Q235B — flat bar feedstock with mill certificates
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NAAMM MBG 531 — load & deflection tables (uniform + concentrated load, L/200)
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EN 1090-1/-2 — structural steel execution, CE-marked assemblies
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ISO 9001:2015 — quality management system, audited annually
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MTC (EN 10204 3.1) material test certificate with every shipment
Ordering terms at a glance
1 pallet (approx. 20 m²) for stock sizes; custom sizes from 100 m²
15–25 days after drawing confirmation
20GP ≈ 26–28 t · 40HQ ≈ 26 t (varies with panel size)
FOB Shanghai / Ningbo · CIF & DDP available on request
T/T 30% deposit, L/C at sight for orders over USD 50,000
Hot-dip galvanizing is what makes carbon steel grating an outdoor product: a metallurgical zinc layer — not paint — that protects the steel cathodically even where the coating is nicked. This page gives the specific numbers most suppliers skip: actual zinc thickness per ASTM A123, salt-spray hours, expected coating life by environment, and the galvanized vs stainless vs aluminum decision in one place.
What ASTM A123 actually guarantees
ASTM A123 is the US standard for hot-dip galvanized fabricated articles. For grating made from 3–5 mm material it requires a minimum average coating of 65–70 µm (2.6–2.8 mils) on the steel surface. We run 70–85 µm by controlling bath immersion time and steel surface prep to ASTM A385 (degrease + acid pickle + flux).
Every lot ships with a galvanizing certificate. Two tests matter: thickness (magnetic gauge per ASTM E376, min 5 readings per panel) and adhesion — the hammer-and-dedge test per ASTM A123 shows no flaking. Zinc spangle size and brightness are cosmetic, not protective: dull grey coatings protect exactly as well as shiny ones, and dull grey is actually the sign of heavier reactive steels (Si > 0.03%).
Why the cut edges do not rust
The most common buyer question. Zinc protects two ways: as a physical barrier, and cathodically — zinc is anodic to steel, so at any scratch or cut edge the zinc corrodes preferentially and deposits protective zinc oxide/hydroxide over the exposed steel. That is why field-cut edges weather to grey but do not run red rust, and why we vent and plug grating before dipping so every weld interior gets coated too.
Galvanized vs stainless vs aluminum
Galvanized carbon steel is the economical default: 40–70 year coating life in most US environments at 1/2 to 1/3 the price of 304 stainless. Choose 304 for washdown hygiene and visible interiors; 316L for coastal, chloride or bleach service. Choose aluminum where weight or handling dominates. And when the environment is wet + chemical rather than merely wet — FRP beats all three.
Frequently asked questions
How thick is the zinc on your galvanized grating?
Will it rust at the cut edges?
How long does galvanized grating last outdoors?
Do you re-galvanize cut-to-size panels?
Is a dull grey coating a defect?
Can I paint over galvanized grating?
Get a quote within 24 hours
Include panel size, load requirement and quantity — or just upload your drawing. Our engineers respond with a price and a load check.
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