Comparing S355J2WP and S355J0W: Understanding the Differences in Steel Grades

Comparing S355J2WP and S355J0W: Understanding the Differences in Steel Grades

When it comes to steel grades, there are countless options to choose from. Two popular choices often compared are S355J2WP and S355J0W. While they may appear similar, these steel grades actually have some notable differences. Understanding these distinctions is crucial for selecting the right steel grade for your specific application.

S355J2WP and S355J0W are both weathering steel grades, which means they are designed to resist corrosion and atmospheric conditions. They are primarily used in outdoor and structural applications, such as bridges, buildings, and even art sculptures. While they share similarities in corrosion resistance, there are a few key distinctions that set them apart.

Chemical Composition:

The chemical composition of a steel grade plays a significant role in its performance and resistance to corrosion. S355J2WP contains higher amounts of phosphorus, copper, chromium, and nickel compared to S355J0W. These alloying elements enhance the steel’s resistance to atmospheric corrosion by forming a protective patina on the surface. The addition of copper, in particular, contributes to the steel’s improved resistance to the elements.

Mechanical Properties:

Another critical factor in distinguishing between S355J2WP and S355J0W is their mechanical properties. Both grades have a minimum yield strength of 355MPa, making them suitable for structural applications. However, S355J2WP has a higher tensile strength than S355J0W, which makes it more durable and better suited for more demanding conditions. The higher tensile strength allows the steel to withstand higher levels of stress and strain, providing a longer service life.


One distinguishing feature between S355J2WP and S355J0W is their designation. “S355” refers to the minimum yield strength of the steel, which is 355MPa. The letter “J” indicates that the steel has been impact tested at -20°C, making it suitable for low-temperature applications. The number “2” in S355J2WP signifies the addition of alloying elements to enhance its atmospheric corrosion resistance. On the other hand, S355J0W, without the designation “2”, indicates a lower level of alloying elements.


Due to their corrosion resistance and mechanical properties, both S355J2WP and S355J0W are commonly used in outdoor structures subject to atmospheric conditions. However, the higher strength and improved resistance of S355J2WP make it ideal for more exposed and demanding environments, such as coastal areas where saltwater and high humidity can cause increased corrosion.

In general, the choice between S355J2WP and S355J0W depends on the specific requirements of your application. If you are looking for a steel grade that can withstand harsher conditions and provide enhanced corrosion resistance, S355J2WP may be the better choice. However, if your application is relatively less demanding and cost is a factor, S355J0W can still provide satisfactory performance.

In conclusion, while S355J2WP and S355J0W may seem similar at first glance, the differences in chemical composition, mechanical properties, and application suitability set them apart. By understanding these distinctions, you can make an informed decision and select the steel grade that best meets your project’s requirements.

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