S235, S275 & S355 Steel Properties and Equivalent Grades

Introduction

S235, S275 and S355 are structural steel grades defined under EN 10025, with different levels of yield strength, tensile strength and chemical composition.

This guide provides a clear overview of S235 S275 S355 steel properties, including yield strength, tensile strength, chemical composition, and equivalent grades (ASTM, JIS, GB). The focus is on technical data and standardized performance values.

S235 S275 S355 Steel Properties Quick Check Table

The table below summarizes the most searched S235, S275 and S355 steel properties, including yield strength, and tensile strength.

Grade	Yield Strength (MPa)	Tensile Strength (MPa)	Elongation (%)
S235	235	360–510	≥26
S275	275	370–530	≥23
S355	355	470–630	≥22

These values represent standard minimum requirements according to EN 10025-2 for thickness up to 16 mm.

S235 S275 S355 Steel Equivalent Grades (ASTM, JIS, GB)

Understanding S235, S275 and S355 steel equivalents is essential for international procurement and cross-standard material selection.

EN Standard	ASTM Equivalent	JIS Equivalent	GB Equivalent
S235JR	ASTM A36	SS400	Q235B
S275JR	ASTM A36 / ASTM A529	SM400A / B	Q275
S355JR	ASTM A572	SM490A / B	Q345B

These equivalents are approximate and should be verified against specific project requirements and standards.

S235 S275 S355 Steel Mechanical Properties (EN 10025)

1. S235, S275 and S355 Yield Strength

The yield strength of S235, S275 and S355 steel is the primary classification basis under EN 10025:

• S235 → 235 MPa
• S275 → 275 MPa
• S355 → 355 MPa

For thicker plates, the minimum yield strength decreases according to standard thickness ranges.

2. S235, S275 and S355 Tensile Strength

Typical tensile strength of structural steel grades:

• S235: 360–510 MPa
• S275: 370–530 MPa
• S355: 470–630 MPa

Higher tensile strength indicates better resistance to deformation under load.

3. Elongation and Weldability of S235, S275 and S355

• S235: Highest ductility and excellent weldability
• S275: Balanced ductility and strength
• S355: Higher strength with slightly reduced formability

All three grades are considered weldable under standard fabrication conditions.

Chemical Composition of S235 S275 S355 Steel (C & Mn)

The chemical composition of S235, S275 and S355 steel contributes to their different mechanical properties and weldability.

Grade	Carbon (C %)	Manganese (Mn %)	Explanation
S235	≤0.17	≤1.40	Low carbon, excellent weldability, lower strength
S275	≤0.21	≤1.50	Slightly higher carbon & manganese, balanced properties
S355	≤0.24	≤1.60	Higher C & Mn levels, resulting in higher yield strength

Engineers should note that while increasing C and Mn enhances yield strength, it can slightly reduce weldability.

S235 S275 S355 Steel Properties Summary

1.S235: Lower strength, with a minimum yield strength of 235 MPa and good ductility and weldability.

2. S275: Intermediate strength, with a minimum yield strength of 275 MPa and a balanced combination of strength and ductility.

3. S355: Higher strength, with a minimum yield strength of 355 MPa and higher load-bearing capacity than S235 and S275.

For a practical understanding of how these grades differ in real projects, including strength comparison, price differences and selection considerations, see our S235 vs S275 vs S355 steel comparison and selection guide.

For a deeper understanding of impact test requirements and the differences between JR, J2 and NL grades, see our S355JR vs S355J2 vs S355NL differences guide.

Frequently Asked Questions

• What are the properties of S355 steel?
  S355 steel has a minimum yield strength of 355 MPa and a typical tensile strength of 470–630 MPa, depending on thickness and grade.
• What are the properties of S275 steel?
  S275 steel has a minimum yield strength of 275 MPa and a typical tensile strength of 370–530 MPa, depending on thickness and grade.
• What are the properties of S235 steel?
  S235 steel has a minimum yield strength of 235 MPa and a typical tensile strength of 360–510 MPa, with good ductility and weldability.
• What is the yield strength of S235, S275 and S355 steel in MPa?
  The yield strength is 235 MPa for S235, 275 MPa for S275 and 355 MPa for S355 under EN 10025 for thickness up to 16 mm.
• What is the equivalent of S355 steel?
  S355 is commonly compared with ASTM A572, JIS SM490 and GB Q345 grades, but the applicable equivalent should be verified against the specific standard and project requirements.
• What is the equivalent of S235 steel?
  S235 is commonly compared with ASTM A36, JIS SS400 and GB Q235B, but these grades should not be treated as automatic one-to-one substitutions.
• What are S275 steel equivalent materials?
  S275 steel equivalents include ASTM A36 or A529, SM400 grades and Q275, with comparable structural performance.