Factory-direct steel gratings & stair treads, shipped worldwide
Heavy Duty Mild Steel Grating
Mild steel heavy duty grating, welded and cut to your sizes.
Q235B low-carbon structural steel · MTC per heat · HDG for exposed duty · Quote within 24 hours
Mill made, factory direct
Welded and press-locked in-house on traceable steel
Certified & tested
Reports on request — heavy duty lots tested
Samples in 5–7 days
Production in 15–25 working days
FOB Tianjin
Mill ~400 km from port, shipped worldwide
Grade comparison
What “Mild Steel” Means on a Heavy Duty Drawing
Heavy duty is a duty decision — deeper bars, closer centers, shorter spans. Mild steel is the grade decision, and it is the one that decides weldability, traceability and finish. This page is the grade view: which steel the heavy duty steel bar grating is actually cut from, and what documents prove it.
| Grade option | What buyers call it | Welding & fabrication | Corrosion behavior | Traceability |
|---|---|---|---|---|
| Q235B mild steel | Mild steel, carbon steel, low-carbon structural steel | Low-carbon and weldable without special preheat; cuts, notches and bands cleanly | Bare steel needs paint, shelter or zinc where water stands | MTC EN 10204 3.1 per heat, checked at goods-in |
| Q235B + hot-dip galvanized | Galvanized heavy steel grating | Same weldable base grade; coating applied after fabrication | Zinc coating metallurgically bonded for exposed and washdown duty | MTC per heat plus HDG coating thickness sampled per batch |
| SS304 stainless | Stainless heavy duty grating | Welded with matched filler; fabrication takes more care | Corrosion-resistant across most washdown duty | MTC per heat; same five-stage QC plan |
| SS316 stainless | 316 heavy duty grating | Welded with matched filler; fabrication takes more care | Strongest option against chlorides and coastal air | MTC per heat; same five-stage QC plan |
“Mild steel”
Trade shorthand for low-carbon structural steel — the family that welds cleanly, bends without cracking and carries load. It is the default heavy duty grating material worldwide.
Q235B, in our mill
The Chinese structural carbon standard is what our lines actually run: specified by yield strength, impact-verified at the B quality tier, bought per heat with a mill test certificate.
A36-comparable framing
US drawings usually express the same role as ASTM A36 low-carbon steel. Equivalents are confirmed in your quote, so the grade column of your spec sheet matches your drawings.
Grade already fixed on your drawings? Send them with the heat certificate requirement — the 24-hour quote confirms the exact grade and its equivalent.
Duty on the grade
How Heavy Duty Is Built on Mild Steel
1 · Deeper bars, closer centers
Heavy duty is geometry, not a different metal: the deep-bar end of our 20×3 mm to 100×8 mm mild steel range, at 30 or 40 mm centers, with spans shortened to suit the load. Open mesh that sheds water and debris stays.
2 · Welded or press-locked, one grade
The same Q235B bar runs on both in-house processes — electro-forged welding for heavy duty open mesh, or press-locking where a close pattern is specified. No third-party panel sourcing, so the heat trail never breaks.
3 · HDG for exposed heavy duty
Heavy steel grating that lives outdoors, over trenches or in washdown zones should ship galvanized: ASTM A123 / ISO 1461 hot-dip galvanizing at a certified partner near our mill — typically 2–3 days, already counted inside your production window, coating thickness sampled per batch.
Why specify mild steel heavy duty
Why Engineers Specify Heavy Duty Mild Steel Grating
Full heavy duty specs
Bar depth, thickness, centers, span and finish quoted against your loads — not a stock chart you have to reverse-engineer. Request heavy duty grating specs with your quote and the panel data arrives itemized with it.
Custom cut to your drawings
Mill-made panels cut and banded to your drawings, notched and drilled where the steelwork demands it. Drawing review is free and included in the 24-hour quote; small trial orders are welcome.
Tested and documented lots
Certified & tested, reports on request — heavy duty lots tested, with a mill test certificate per heat and a factory inspection report with every shipment. The grade on your drawing is the grade in the certificate.
Applications
Where Heavy Duty Mild Steel Grating Works
Wherever wheels, pallets or trolleys cross an open steel floor and the environment is dry, painted or galvanized — mild steel heavy duty panels are the economical structural answer.
Heavy plant flooring
Deep-bar panels taking trolley and forklift traffic on plant floors and loading bays.
Platforms & mezzanines
Heavy duty steel bar grating floors over plant, rated by span and bar depth rather than guesswork.
Trench covers under wheels
Yard and dock trenches crossed by vehicles — order HDG where water sits in the channel.
Heavy duty stair treads
Serrated or plain Q235B treads, banded with end plates, drilled ready to bolt on access stairs.
Specifications
Heavy Duty Mild Steel Grating Specifications
| Parameter | Range |
|---|---|
| Grade | Q235B low-carbon (mild) steel · SS304 / SS316 on request |
| Bearing bar | 20×3 mm to 100×8 mm, plain or serrated — heavy duty at the deep-bar end |
| Bar spacing | 30 / 40 / 60 mm centers |
| Cross bar | Twisted square or round, per specification |
| Panel width | Up to 1.25 m |
| Panel length | Up to 6 m |
| Surface | Black, painted, or hot-dip galvanized (ASTM A123 / ISO 1461) |
| Documents | MTC EN 10204 3.1 per heat · factory inspection report |
Grade & traceability documents
Every heat of Q235B enters the workshop with its mill test certificate verified at goods-in — the first of our five QC stages. Heavy duty mild steel panels leave with paperwork your engineering team can audit:
- Mill test certificate to EN 10204 Type 3.1, one per heat
- Grade and equivalent confirmed in writing with your quote
- Factory inspection report with every shipment
- Declaration of Conformity prepared per order destination
Standards & compliance
Produced to Recognized Standards — Documents on Request
ANSI / NAAMM references
Heavy duty panels produced to ANSI/NAAMM MBG 531 reference practice; MBG 532 heavy-duty references quoted per project — say which you need in your RFQ.
ASTM A123 / ISO 1461 HDG
Galvanized coating thickness checked by sampling on every galvanized batch before heavy duty panels are released.
CE & SGS tested
Certified & tested, reports on request — we show documents you can verify, not a certificate wall.
Custom made
Heavy Duty Panels, Cut and Banded to Your Drawings
Send your drawing
Panel sizes, spans, loads, grade and finish — or just photos and a sketch. Drawing review is free.
Quote within 24 hours
Itemized, FOB Tianjin as standard — EXW or CIF on request. The grade and its equivalent are confirmed here, any size or quantity.
Samples in 5–7 days, production in 15–25
Working days after drawing confirmation, hot-dip galvanizing included. Installation drawings and fixing layout ship with the order.
Factory-direct quote
Get a Factory Quote
Request heavy duty grating specs today — the itemized quote, panel data and grade confirmation land within 24 hours.
- Q235B mild steel with MTC EN 10204 3.1 per heat
- Certified & tested, reports on request — heavy duty lots tested
- Factory audits welcome — see the lines before you commit
Prefer to talk? WhatsApp us or sales@dtsteelladder.com
Request your quote
Five fields — we do the rest.
FAQ
Frequently Asked Questions
What grade is mild steel in heavy duty grating?
Mild steel means low-carbon structural steel. In our mill that grade is Q235B, the Chinese structural carbon standard — the same role ASTM A36 low-carbon steel plays on US drawings. The exact grade and its equivalent are confirmed in your quote, backed by a mill test certificate for every heat.
Should heavy duty mild steel grating be galvanized?
Yes for any exposed or washdown duty. Q235B is a galvanizer-friendly carbon steel: hot-dip galvanizing to ASTM A123 / ISO 1461 runs at a certified partner near our mill, typically 2–3 days and already counted inside the 15–25 day production window. Indoor or sheltered floors can ship black or painted.
What are the lead time and order minimums?
Samples ship in 5–7 working days and mass production runs 15–25 working days after drawing confirmation, hot-dip galvanizing included. Small trial orders are welcome, full-container orders are calculated per loading plan, and an itemized FOB Tianjin quote arrives within 24 hours.
Related pages
Related Grating Pages
Heavy-Duty Grating
The duty fundamentals: what changes in bars, spans and wheels.
View page →Heavy Duty Bar Grating
The bar construction view — depths, thicknesses and centers.
View page →Heavy-Duty Welded Grating
Electro-forged panels at heavy duty ratings.
View page →Heavy Duty Steel Floor Grating
The floor application view of the same duty class.
View page →Q235 Steel Grating
The grade page in full: chemistry, MTC and finish options.
View page →Carbon Steel Bar Grating
Carbon steel compared across grades and environments.
View page →