Tianjin Brisk Metalwork Co., Ltd. is one of the leading manufacturers and suppliers of s355 structural hollow section in China. We have world-leading production equipment and strong manufacturing capabilities. Please feel free to buy bulk durable s355 structural hollow section from our factory.
S355 is not owned by one standard - it appears, with slightly different delivery conditions, across several:
- EN 10210 - hot-finished structural hollow sections (S355J2H, S355NH, S355NLH), seamless or welded-and-normalized
- EN 10219 - cold-formed welded structural hollow sections (S355JR, S355J0H, S355J2H, S355NH, S355NLH)
- ASTM A500 Grade C - the nearest US cold-formed equivalent, minimum yield 50ksi (~345MPa), close but not identical to S355
The production route and the standard, not the grade number, are what actually change the mechanical guarantee you get. Two pipes both marked "S355" can differ significantly in toughness and residual stress depending on whether they came off a hot-finished EN 10210 line or a cold-formed EN 10219 line - the grade tells you the yield strength floor, not the full delivery condition.
This is where buyers most often order the wrong thing without realizing it:
- JR / J0 / J2 / K2 - impact-test temperature and energy under EN 10219: JR (room temp, minimal guarantee), J0 (0degC), J2 (-20degC), K2 (-20degC, higher energy requirement)
- NH / NLH - impact-test temperature under EN 10210's normalized designation: NH (0degC), NLH (-20degC or colder on request)
- H - simply confirms the section is a hollow section product under that standard, as opposed to plate or open-section steel
If your project spec just says "S355" with no suffix, we will ask which standard and impact-test requirement applies before quoting - guessing wrong here is the single most common cause of certificate rejections we see at the receiving end.
What Shapes and Sizes Do We Produce in S355?
- Square (SHS): 20 x 20mm up to 600 x 600mm, wall thickness 1.5mm - 50mm
- Rectangular (RHS): 30 x 20mm up to 800 x 400mm, wall thickness 1.5mm - 50mm
- Circular (CHS): 21.3mm - 610mm OD (larger available via our welded route), wall thickness 2mm - 40mm
- Standard lengths: 6m and 12m, with random or fixed lengths on request
Both seamless and welded execution are available in S355, and both cold-formed (EN 10219) and hot-finished (EN 10210) delivery conditions are in regular production here - we are not limited to a single route for this grade.
Seamless or Welded - How Do We Decide for an S355 Order?
For square and rectangular S355 sections, we form from coil below roughly 500 x 500mm using our own tube mills, and switch to plate-formed LSAW tube reshaped into box section above that. For circular S355 sections, we run genuinely seamless pipe below our piercing-mill ceiling (roughly 400-450mm OD) and welded-and-normalized pipe above it. The route we select never changes the guaranteed mechanical properties on your certificate - it changes lead time and, at some size/grade combinations, price. We will tell you upfront which route your order falls into so there are no surprises at quotation stage.
Why Do Buyers Specify S355 Instead of a Lower Grade?
The most common reason is weight, not strength for its own sake. Moving from S235 to S355 lets a structural designer reduce wall thickness while keeping the same load capacity, which cuts steel tonnage, freight cost, and welding time. On a large frame or bracing package, that reduction compounds fast - a project that would need a 12mm wall in S235 can often be built with a 9mm or even 8mm wall in S355, carrying the same design load.
The trade-off is that S355 costs more per tonne than S235, so it only pays off once the tonnage or freight saving outweighs the unit-price difference - which is exactly the calculation we help buyers run when they send us a load spec instead of a grade number already decided.
How Do We Control Quality Across Our S355 Range?
- Heat/batch chemistry verification against the target grade before forming
- In-line dimensional monitoring (OD/size, wall thickness, straightness) during production
- Weld seam ultrasonic testing on all welded S355 product, pre- and post-heat-treatment where normalizing applies
- Batch mechanical testing - yield, tensile, elongation, and Charpy impact at the temperature the suffix requires (0degC for NH/J0, -20degC for NLH/J2/K2)
- EN 10204 3.1 mill certificates, heat-traceable, issued per production batch
A Recent S355 Order, With the Numbers
A structural steel fabricator building a warehouse mezzanine frame originally specified S235 SHS at 10mm wall throughout. After we ran the load numbers against S355J2H, they were able to drop to 7mm wall on the same 200 x 200mm section size - a 30% reduction in steel weight on that member. Across the full order of 340 pieces at 6m length, that cut roughly 11 tonnes off the total shipment weight, which brought the sea-freight cost for that container down proportionally and shortened the welding time their site crew logged by an estimated two days. The certificate still carried the same EN 10219 J2H impact guarantee they needed for their local code - the weight saving came purely from the grade change, not from any compromise on toughness.
FAQ
Q: Is S355 always more expensive than S235 per tonne?
A: Yes, per tonne S355 carries a price premium. Whether the finished structure costs more depends on how much wall thickness (and therefore total tonnage) you can remove by using the higher grade - send us your load requirement and we can help estimate the trade-off.
Q: Can S355 hollow section be hot-dip galvanized?
A: Yes, S355 SHS/RHS/CHS can be supplied hot-dip galvanized to EN ISO 1461 in addition to black or varnish-coated finish.
Q: Do you supply S355 with a certificate covering both EN 10210 and EN 10219 designations?
A: No - each piece is certified under the standard it was actually produced to, since the delivery conditions differ. If your project accepts either standard, tell us and we will quote whichever route gives the better lead time or price.
Q: What is the minimum order quantity for S355 hollow section?
A: It depends on shape, size, and whether the order needs a dedicated production run or fits into an existing coil/billet schedule - smaller common sizes generally have lower thresholds than large-OD or low-temperature NLH orders.
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