What is the difference between P355GH and S355j2?
When engineers and procurement managers look at European standard steel grades, they often get stuck on one confusing question:
"Both P355GH and S355J2 have a minimum yield strength of 355 MPa. They look the same on paper. Can I just use whichever is cheaper or available?"
The short answer is NO.
While they share the same strength level, their DNA (manufacturing standards) , chemical composition, and performance under extreme conditions are completely different.
Selecting the wrong grade can lead to high-temperature creep failure (if you choose S355J2 for a boiler) or brittle fracture in freezing weather (if you choose P355GH for a bridge in Siberia).
In this guide, we break down the exact differences between P355GH and S355J2 so you can make the right call-and avoid legal liability or safety disasters.
The Core Difference – Pressure vs. Structure
1. Standard Specifications (The Most Critical Difference)
| Feature | P355GH | S355J2 |
|---|---|---|
| Standard | EN 10028-2 | EN 10025-2 |
| Application | Pressure vessels, boilers, heat exchangers | Bridges, cranes, buildings, wind towers |
| Key Requirement | Elevated temperature properties + rigorous NDT (non-destructive testing) | Impact toughness at -20°C only |
2. Chemical Composition Comparison
Even though both are non-alloy steels, the "recipe" varies significantly to serve different working conditions.
| Element | P355GH (Pressure Grade) | S355J2 (Structural Grade) | Why it matters |
|---|---|---|---|
| Carbon (C) | ≤ 0.18% | ≤ 0.22% | Lower carbon in P355GH = better weldability for thick walls. |
| Sulfur (S) | ≤ 0.010% | ≤ 0.035% | This is the big differentiator. P355GH has ultra-low sulfur to prevent hot cracking during welding of pressure parts. |
| Alloying elements | Micro additions of Mo (Molybdenum) , Nb | Simple C-Mn system | Molybdenum in P355GH improves high-temperature strength (creep resistance). |
Pro Insight: If your project requires Post-Weld Heat Treatment (PWHT) , P355GH is far superior. S355J2 has a higher risk of reheat cracking under PWHT.
Application Scenarios – When to Use Which?
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P355GH Applications (High Temperature & Pressure)
The "GH" in P355GH stands for "Elevated Temperature properties" .
Boiler drums – Long-term exposure to 400°C high-pressure steam.
Oil refinery reactors – High temperature + corrosive media.
Heat exchanger shells.
LPG storage tanks (specifically for the high-strength requirement).
S355J2 Applications (Load-bearing & Cold Climates)
The "J2" in S355J2 means "27J impact energy at -20°C" .
Construction machinery – Excavator booms, crane arms.
Bridges in cold regions – Northern Europe, Canada, Russia.
Wind turbine towers – Fatigue resistance + low temperature.
Offshore structures.
Mechanical Properties – Side by Side (Data Table)
| Property | P355GH | S355J2 | Winner |
| Yield Strength (≤16mm) | ≥ 355 MPa | ≥ 355 MPa | Tie |
| Tensile Strength (≤16mm) | 510 – 650 MPa | 470 – 630 MPa | P355GH (higher minimum) |
| Impact Test Temperature | 0°C (≥ 34J) | -20°C (≥ 27J) | S355J2 for low temp; P355GH for room/high temp |
| High Temperature (400°C) | Excellent (Designed for creep resistance) | Poor (Strength drops rapidly) | P355GH |
| Delivery Condition | Normalized (N) mandatory | As-rolled or normalized | P355GH (more stable grain structure) |
why choose us?
YUXIN GROUP is a reliable supplier of EN standards steel plates with competitive pricing.
Our advantages:
Full sizes: 6mm – 150mm thickness | 1500mm – 3500mm width
Certifications: EN 10204 3.1 | Third-party inspection (BV, SGS, ABS) accepted
Processing: Laser cutting, normalized heat treatment, UT (ultrasonic testing)
Download the technical datasheet (PDF)one-stop solution
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Tianjin, China
Phone Number
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FAQ
01.What is the Chinese equivalent of P355GH?
02.Can S355J2 be used for pressure vessels?
03.Can I weld P355GH to S355J2?
04.What is the difference in price between P355GH and S355J2?
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Through years of understanding and precipitation of steel, Yuxin Group has now become a mature steel processing and manufacturer, providing various products for many construction companies and steel structure companies around the world. Thanks to Yuxin Group's professionalism and integrity, it has become a world-renowned enterprise.
