What is the difference between steel material grades Q195 Q235 Q355?

Differences between steel grades Q195, Q235, and Q355

Steel is divided into different grades according to its chemical composition and mechanical properties to meet the needs of various engineering applications. In China, common carbon structural steel (Carbon Structural Steel) is divided into multiple grades according to the national standard GB/T 700, among which Q195, Q235 and Q355 are the three most commonly used grades. The main difference between each grade lies in its minimum yield strength (Yield Strength), tensile strength (Tensile Strength), elongation (Elongation) and scope of application.

1. Q195

Yield strength: ≥195 MPa

Tensile strength: ≥345 MPa

Elongation: ≥26%

Features:

The yield strength is low, suitable for ordinary structural parts with low strength requirements.

The elongation is high, with good plasticity and processing performance.

Application areas:

Mainly used for general-purpose steel structures, such as light buildings, simple brackets, etc.

Also commonly used in the manufacture of electric poles, scaffolding, guardrails, etc.

2. Q235

Yield strength: ≥235 MPa

Tensile strength: ≥375 MPa

Elongation: ≥24% (Grade A) or ≥22% (Grade B)

Features:

Compared with Q195, Q235 has higher yield strength and tensile strength, suitable for a wider range of structural applications.

It has good weldability and cold formability, and is easy to process.

Application areas:

Widely used in construction, bridges, ships, machinery manufacturing and other fields.

Suitable for making structural parts such as beams, columns, frames, pipes, containers, etc.

3. Q355

Yield strength: ≥355 MPa

Tensile strength: ≥470 MPa

Elongation: ≥20%

Features:

It has significantly higher yield strength and tensile strength, suitable for complex structures with high mechanical properties.

Good toughness and low-temperature impact performance, able to remain stable in harsh environments.

Application areas:

Mainly used in key structures such as heavy buildings, large bridges, high-rise buildings, high-pressure vessels, mining machinery, etc.

Suitable for occasions with large stress and dynamic loads, such as crane arms, pressure pipes, etc.


grade	Yield Strength (MPa)	Tensile Strength (MPa)	Elongation (%)	Application Areas
Q195	≥195	≥345	≥26	Lightweight construction, simple support, etc.
Q235	≥235	≥375	≥24 (Grade A) or ≥22 (Grade B)	Construction, bridges, ships, machinery manufacturing, etc.
Q355	≥355	≥470	≥20	Heavy buildings, large bridges, high-pressure vessels, etc.

Selection suggestions

Q195: Suitable for general-purpose structural parts with low strength requirements, with high cost-effectiveness.

Q235: Widely applicable to various structural parts with medium strength requirements, with good processing performance.

Q355: Suitable for key structural parts with high strength and high toughness requirements, ensuring safety and reliability in long-term use.