Steel Grating
Welded, press-locked and riveted steel grating panels — hot-dip galvanized carbon steel, 304/316L stainless, aluminum or FRP — cut to your drawing for walkways, platforms, stair treads and trench covers.
Get a Quote Download CatalogStandard welded steel grating sizes & load data
Screenshot-ready. Every dimension below is a standard tooling size — custom spacings are cut to your drawing at no extra mold cost.
| Type (19W4 style) | Bearing bar (mm) | Pitch (mm) | Weight (kg/m²) | Max span @ 100 psf |
|---|---|---|---|---|
| G253/30/100 | 25 × 3 | 30 × 100 | 22.4 | 1.05 m |
| G303/30/100 | 30 × 3 | 30 × 100 | 26.5 | 1.25 m |
| G323/30/100 | 32 × 3 | 30 × 100 | 28.2 | 1.35 m |
| G325/30/100 | 32 × 5 | 30 × 100 | 42.8 | 1.60 m |
| G403/40/100 | 40 × 3 | 40 × 100 | 24.6 | 1.45 m |
| G405/40/100 | 40 × 5 | 40 × 100 | 39.6 | 1.85 m |
| G505/50/100 | 50 × 5 | 50 × 100 | 34.8 | 2.20 m |
| G655/50/100 | 65 × 5 | 50 × 100 | 43.5 | 2.90 m |
Type naming: G = grating, first digits = bearing bar height, second group = bar thickness (mm), then cross-bar pitch / bearing pitch (mm). Custom pitches and 60°/45° twisted square cross bars available.
Choose your construction and material
Each family has its own load table, finish options and lead time.
Welded Bar Grating
The default: bearing bars resistance-welded to twisted square cross bars. Strongest per kg.
View series → Product FamilyStainless Steel Grating
304 for general chemical and food plants, 316L for marine and high-chloride media. KD is low — the fastest page to rank.
View series → Product FamilyGalvanized Steel Grating
Hot-dip zinc 70–85 µm per ASTM A123 — the workhorse for outdoor walkways and trench covers.
View series → Product FamilySerrated Steel Grating
Serrated top surface for wet and oily floors. Accept 10–15% lower load capacity for far better grip.
View series → Product FamilyAluminum Grating
6061-T6, about 1/3 the weight of steel — for weight-critical and corrosion-free platforms.
View series → Product FamilyFiberglass (FRP) Grating
Molded or pultruded GRP — non-conductive, non-sparking, corrosion-free.
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 |
Load & deflection — carbon steel, 30/100 pitch
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.
| Bearing bar (mm) | Uniform load (kN/m²) @ 1 m span | Concentrated load (kN) @ 1 m | Deflection @ L/200 |
|---|---|---|---|
| 25 × 3 | 6.6 | 3.1 | 5.0 mm |
| 32 × 3 | 11.0 | 5.1 | 5.0 mm |
| 32 × 5 | 18.3 | 8.5 | 5.0 mm |
| 40 × 3 | 17.2 | 8.0 | 5.0 mm |
| 40 × 5 | 28.7 | 13.3 | 5.0 mm |
| 50 × 5 | 44.9 | 20.8 | 5.0 mm |
Calculated to NAAMM MBG 531, simply supported, deflection limited to L/200. Download the full table for other spans and pitches in the catalog.
Where steel grating works hardest
Reference projects available per industry on request.
Elevated walkways & catwalks
Standard 30/100 panels with toe plates, clip-fixed to support steel.
Machine platforms
Heavy 50×5 and 65×5 sections for point loads from equipment.
Trench covers
Galvanized frames with spring-loaded or bolt-down fixing.
Stair treads
Serrated treads with anti-slip nosing, OSHA compliant.
Chemical & petro plants
316L stainless around chlorides and acids; FRP around electrolytes.
Power & substations
Non-sparking FRP or aluminum where grounding is an issue.
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.
✓
ASTM A36 — carbon structural steel bar and plate
✓
ASTM A123 — hot-dip galvanizing, 70–85 µm zinc coating on bearing bars
✓
ASTM A1011 / Q235B — flat bar feedstock with mill certificates
✓
NAAMM MBG 531 — load & deflection tables (uniform + concentrated load, L/200)
✓
EN 1090-1/-2 — structural steel execution, CE-marked assemblies
✓
ISO 9001:2015 — quality management system, audited annually
✓
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
Steel grating is a load-bearing open-mesh floor made from parallel bearing bars joined by cross bars — the standard industrial surface for anywhere people, loads and liquids share the same space. Since 2009 we have shipped welded, press-locked and FRP grating from our Ningbo factory to contractors, fabricators and distributors across North America.
Every panel is made to order: you choose bearing bar size, pitch, material and finish, and we cut, band and drill to your DXF or DWG drawing — with an engineer-signed load check to NAAMM MBG 531 before production starts.
How steel grating is made
Welded grating — 80% of what we ship — is produced on automatic press-welding lines: bearing bars are fixtured at pitch, twisted square cross bars are hydraulically pressed into them, and every intersection is resistance-welded. The panel is then straightened, edge-flattened, cut to size and hot-dip galvanized to 70–85 µm zinc.
Press-locked and swage-locked grating are formed by mechanically locking the cross bars into slotted bearing bars — no heat, no weld. Riveted grating assembles bearing and cross bars with cold rivets. See the welded vs press-locked comparison for the trade-offs in load, cost and removability.
Choosing the right grating in 4 steps
The fastest way to spec grating is to fix four variables in order:
- Load — uniform (kN/m²) or concentrated (kN) load, and span between supports. This fixes the bearing bar height and thickness.
- Environment — indoors/dry → painted or mill carbon steel; outdoors → hot-dip galvanized; chloride/chemical → 316L or FRP; electrolytic → FRP.
- Safety — wet, oily or sloped surfaces → serrated surface and note the 10–15% capacity reduction.
- Fixing & edge — clip type, banding (closed ends), toe plates, and clamp quantity per m².
Why buy factory-direct from China
Distributor pricing on standard 19W4-style welded grating typically runs 30–60% above FOB factory pricing once you include their margin. Buying factory-direct you get: a mill certificate (MTC EN 10204 3.1) with every heat number, a load table signed by our engineer for your exact span, custom sizes at no mold cost, and 15–25 day production.
Shipping: a 20GP loads roughly 26–28 t of panel; a 40HQ about the same weight but twice the volume for lighter FRP or aluminum. We ship FOB Shanghai or Ningbo, and can quote CIF to any US port. Third-party pre-shipment inspection (SGS, BV, TÜV) is welcome on any order.
Frequently asked questions
What is the standard size of a steel grating panel?
What does 19W4 mean?
How do I know which bearing bar size I need?
What is your MOQ?
Can you match grating I bought from a US distributor?
Do you provide load calculations with the shipment?
How long does hot-dip galvanizing last outdoors?
What is the difference between steel grating and bar 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.
Attach your file, then send the form — your email client will open with the details pre-filled. For files over 10 MB, email sales@promptbarn.com directly.
✓ Your email client has opened with the RFQ details. Didn't open? Write to sales@promptbarn.com.