S355 and A572 Steel Plate Cutting: European and North American Grade Comparison
S355 and A572 Gr.50 are the default structural steel grades in Europe and North America. In international sourcing, both are commonly compared with Q355 under Chinese national standards — but chemistry, testing, certification, and project requirements may differ, so the exact specification must be confirmed before production.
Understanding the Grade Comparison
S355 (EN 10025), A572 Grade 50 (ASTM A572), and Q355 (GB/T 1591) are structural steel grades with comparable yield-strength levels — in the 345–355 MPa range for thinner plate. They are produced to different national standards and serve similar structural applications.
The comparison is common in international steel sourcing, but these grades are not automatically interchangeable. Chemistry limits, impact testing requirements, certification formats, and project specifications may differ. YUNCUT reviews each project against the buyer's exact standard and subgrade before production.
Grade Comparison at a Glance
| Property | S355 (EN) | A572 Gr.50 (ASTM) | Q355 (GB) |
|---|---|---|---|
| Min. yield strength | 355 MPa (≤16mm) | 345 MPa | 355 MPa (≤16mm) |
| Min. tensile strength | 470–630 MPa | 450 MPa | 470–630 MPa |
| Standard | EN 10025 | ASTM A572 | GB/T 1591 |
| Cutting behaviour | Generally comparable — confirm against your project specification | ||
Cutting Parameters: Similar Family, Confirmed per Project
Because these grades share a similar strength family, cutting parameters are generally close. Laser and flame cutting conditions are still confirmed per project against the exact standard, subgrade, thickness, and tolerance requirement — not assumed from the grade name alone.
The same review applies to flame cutting. Whether you order S355, A572 Gr.50, or Q355, edge condition, tolerance, and any heat-affected-zone requirements should be discussed with the production team before cutting starts.
How to Order Using Your Local Grade Name
At YUNCUT, buyers specify their grade using their local standard — S355 for European buyers, A572 Gr.50 for North American buyers. We review the specification and source to the commonly compared Chinese standard grade (Q355), confirming chemistry and mechanical requirements against your project before production. A Chinese mill certificate confirming grade, heat number, and mechanical properties is provided.
If your project specification requires a certificate in EN 10025 or ASTM A572 format rather than a Chinese mill certificate, this must be confirmed at quotation stage. Third-party inspection options and certificate formats are discussed at quotation — they should be confirmed before production, not after.
Common Applications
- Structural connections: gusset plates, base plates, splice plates
- Offshore and marine structures: deck plates, stiffeners, bulkheads
- Heavy equipment frames and chassis
- Bridge secondary structural components
- Industrial building structural steel
Quality and Certification
Standard: Chinese mill certificate confirming Q355 grade, heat number, and mechanical properties. Available on request: third-party dimensional inspection report. By arrangement: third-party inspection and certificate formats matching EN 10025 or ASTM A572 project requirements. Confirm certification requirements at quotation stage — they should be confirmed before production.