Keep the K2 requirement in the specification
S355K2W belongs to the S355 family of structural steels with improved atmospheric corrosion resistance under EN 10025-5. Its K2 designation differentiates the impact-quality requirement from S355J2W.
K2 specifies a higher Charpy impact-energy requirement than J2 at the same test temperature. It does not, by itself, mean higher yield strength, better corrosion resistance or a universal minimum service temperature. Plate thickness, delivery condition and the project design remain part of material selection.
Specification checkpoints
| Item | What to specify |
|---|---|
| Full grade | S355K2W, including the delivery condition specified by the project. |
| Product reference | EN 10025-5; confirm the governing standard edition. |
| Dimensions and tolerances | Provide plate thickness, width, length, quantity and any additional tolerance requirements. |
| Toughness acceptance | Specify applicable K2 testing, orientation, specimen requirements and project additions. |
| Fabrication | Describe welding, bending, thermal cutting and any planned heat treatment for technical review. |
| Documents and traceability | Define inspection reports, material identification and any project hold points before order. |
Prepare a complete S355K2W inquiry
Identify the delivery condition before comparing offers. Processing guidance or thickness limits for one producer's specific product should not be transferred to every S355K2W plate.
- Full grade, governing standard edition and required condition
- Thickness × width × length and quantity for every line item
- Drawing revision, cut-edge requirements and machining allowance
- Impact-test and other inspection requirements from the project
- Welding or forming plan and the required material identification
Send your destination, delivery basis and requested schedule with the size list. Processing scope, available sizes, inspection documents and lead time are confirmed against the enquiry before an order is agreed.
Applications defined by the design
- Exposed structural platework with an explicit K2 requirement
- Fabricated load-bearing components covered by approved engineering drawings
- Infrastructure plate inquiries specifying S355K2W and an agreed condition
Confirm design suitability and fabrication procedures with the responsible engineer. Weathering steel still needs suitable exposure, drainage and drying; its grade designation does not remove those detailing requirements.
Frequently asked questions
Why specify K2 instead of J2?
The project may require a different impact-energy acceptance level. Preserve the designer's requirement; choose neither quality from surface appearance alone.
Is every S355K2W plate supplied in the same condition?
No single condition is promised by this listing. State the required condition in the inquiry and confirm it in the quotation and order documents.
Can this grade be welded or formed?
Provide the actual thickness, delivery condition and fabrication plan for review. The fabricator should use qualified procedures appropriate to the material and project.
Compare weathering-steel references ↗
Material certificate checklist ↗
Understand the weathering surface ↗
The project specification, agreed standard edition, delivery condition and order-specific inspection requirements govern supply. A surface color or similar grade name does not establish equivalence.
