What is S420J0?
S420J0 is a high-strength, low-alloy structural steel grade standardized under EN 10025-2.
"S" = Structural steel
"420" = Minimum yield strength of 420 MPa
"J0" = Charpy impact energy of 27 J at 0°C, providing good low-temperature toughness.
It is widely used in bridges, heavy engineering structures, cranes, and building frameworks due to its high strength, weldability, and toughness.
1. Mechanical Properties
| Property | Value / Requirement | Standard / Notes |
|---|---|---|
| Yield Strength (ReH) | ≥ 420 MPa | EN 10025-2 |
| Tensile Strength (Rm) | 520–680 MPa | EN 10025-2 |
| Elongation (A5) | ≥ 17–20% | Typical for structural steel |
| Impact Energy (Charpy V-notch) | ≥ 27 J at 0°C | "J0" rating |
| Hardness (HB) | 150–200 HB | Brinell hardness |
| Density | 7.85 g/cm³ | Standard steel value |
| Modulus of Elasticity | 210 GPa | Typical for structural steel |
2. Chemical Composition (Typical % by weight)
| Element | C | Si | Mn | P | S | N |
|---|---|---|---|---|---|---|
| % | 0.22 | ≤0.55 | 1.60 | ≤0.035 | ≤0.035 | ≤0.012 |
What is S355J0?
What is S355J0?
S355J0 is a high-strength, non-alloy structural steel standardized under EN 10025-2.
"S" = Structural steel
"355" = Minimum yield strength of 355 MPa
"J0" = Charpy impact energy of 27 J at 0°C, providing good low-temperature toughness
It is widely used in bridges, building structures, and heavy engineering applications, offering excellent weldability, machinability, and moderate low-temperature performance.
1. Mechanical Properties
| Property | Value / Requirement | Standard / Notes |
|---|---|---|
| Yield Strength (ReH) | ≥ 355 MPa | EN 10025-2 |
| Tensile Strength (Rm) | 470–630 MPa | EN 10025-2 |
| Elongation (A5) | ≥ 20% | Typical for structural steel |
| Impact Energy (Charpy V-notch) | ≥ 27 J at 0°C | "J0" rating |
| Hardness (HB) | 140–190 HB | Brinell hardness |
| Density | 7.85 g/cm³ | Standard steel value |
| Modulus of Elasticity | 210 GPa | Typical for structural steel |
2. Chemical Composition (Typical % by weight)
| Element | C | Si | Mn | P | S | N |
|---|---|---|---|---|---|---|
| % | 0.22 | ≤0.55 | 1.60 | ≤0.035 | ≤0.035 | ≤0.012 |
What is the difference of them?
S420J0 vs S355J0
| Feature | S355J0 | S420J0 |
|---|---|---|
| Yield Strength (ReH) | ≥ 355 MPa | ≥ 420 MPa |
| Tensile Strength (Rm) | 470–630 MPa | 520–680 MPa |
| Impact Energy (Charpy V) | ≥ 27 J at 0°C | ≥ 27 J at 0°C |
| Low-Temperature Use | Moderate low-temperature toughness | Moderate low-temperature toughness |
| Weldability | Excellent | Excellent |
| Typical Applications | Bridges, building frameworks, general structural steel | Bridges, heavy-duty structures, cranes, high-load applications |
Key Differences
Strength: S420J0 has higher yield and tensile strength than S355J0, allowing lighter, stronger structures for heavy-duty applications.
Applications: S355J0 is suitable for moderate structural loads, while S420J0 is preferred for high-load, heavy engineering structures.
Other Properties: Both grades share good weldability and toughness at 0°C, but S420J0's higher strength provides a better strength-to-weight ratio.
GNEE Steel also supplies a variety of high-strength steel plates, such as A514 Grade F, A572 Grade 50, A588 Grade A, S355JR, S690Q, SS400, S690QL, Q345B, Q345E, etc. If you want to know more about other types of steel plates, you can call the consultation hotline at +8615824687445 or send an email to info@gneesteels.com. You are welcome to consult us, and we are very willing to answer your questions.
