S275JR steel channel and S355JR steel channel are low-alloy structural steel sections manufactured in accordance with EN 10025-2. Both grades are widely used for load-bearing structures such as building frames, steel platforms, machinery bases, and infrastructure projects.
In the steel designation system:
"S" stands for structural steel
"275" and "355" indicate the minimum yield strength in MPa
"JR" means the steel is impact tested at +20 °C with a minimum energy of 27 J
S275JR steel channel
Accordingly, S275JR steel channel has a minimum yield strength of 275 MPa, while S355JR steel channel provides a higher minimum yield strength of 355 MPa, making it more suitable for higher load and weight-reduction designs.
Chemical Composition Difference between S275JR and S355JR Steel Channel (%)
Although both channels belong to the same EN 10025-2 family, their chemical composition limits differ slightly to support different strength levels.
| Grade | C (t ≤16mm) | Si | Mn | P | S | Cu | N |
|---|---|---|---|---|---|---|---|
| S275JR Steel Channel | 0.24 max | – | 1.60 max | 0.045 max | 0.045 max | 0.60 max | 0.014 max |
| S355JR Steel Channel | 0.27 max | 0.60 max | 1.70 max | 0.045 max | 0.045 max | 0.60 max | 0.014 max |
Key Chemical Differences for Channels
Carbon (C): S355JR steel channel allows higher carbon content, directly contributing to higher strength
Manganese (Mn): Slightly higher in S355JR, improving hardenability and tensile performance
Phosphorus & Sulfur: Controlled at the same level to maintain weldability and toughness
Mechanical Properties Difference between S275JR and S355JR Steel Channel
The mechanical performance is the main factor when selecting between these two channel grades.
| Grade | Yield Strength ReH (MPa) min | Tensile Strength Rm (MPa) | Elongation A (%) min | Charpy V Impact |
|---|---|---|---|---|
| S275JR Steel Channel | 275 | 410–560 | 23 | 27 J at +20 °C |
| S355JR Steel Channel | 355 | 470–630 | 22 | 27 J at +20 °C |
Practical Difference between S275JR and S355JR Steel Channel
From an application and design standpoint:
S275JR Steel Channel is Preferred When:
Loads are moderate
Cost efficiency is a priority
Standard building frames and light industrial structures are involved
Easy fabrication and forming are required
S355JR Steel Channel is Preferred When:
Higher load-bearing capacity is required
Weight reduction or slimmer structural design is needed
Long-span beams, heavy machinery frames, or infrastructure projects are involved
Structural optimization is important
Although the chemical composition difference is not dramatic, the higher carbon and manganese content in S355JR steel channel directly results in higher strength, which is the key distinction between the two grades.
Both S275JR steel channel and S355JR steel channel are reliable EN 10025-2 structural sections with guaranteed impact toughness at +20 °C. The selection mainly depends on required strength level and structural design needs rather than weldability or basic material quality.
- Choose S275JR steel channel for standard structural applications and cost-effective solutions
- Choose S355JR steel channel when higher strength, reduced weight, or optimized structural performance is required
If you need assistance selecting the right steel channel grade, size, or fabrication condition, a professional manufacturer can provide technical support and material certification according to your project requirements.
Contact us for latest S275JR Mild Steel Channel price list
What is S275JR grade steel?
S275JR grade steel is a readily weldable low carbon manganese steel with good impact resistance. This material is commonly supplied in the untreated or normalised condition. Machinability of this material is similar to that of mild steel.
What is S275JR steel equivalent to?
1 (American Welding Society) permits S275JR as an equivalent to A36 for welding purposes, and they are frequently interchanged in international projects. However, they are not identical: Standards: A36 is governed by ASTM (American), while S275JR follows EN (European), leading to differences in testing requirements.
What type of material is S235JR?
S235JR steel is a low-carbon structural alloy valued for its machinability, strength, and versatility. Perfect for complex components with tight tolerances, it is widely used in CNC machining for mechanical, structural, and industrial applications.
Are A36 and S275JR the same?
Both yield strength and tensile strength of S275JR carbon steel is higher than that of mild steel ASTM A36. So S275JR carbon steel can bear heavier load than mild steel ASTM A36. In other word, mild steel ASTM A36 is not equivalent to S275JR carbon steel.
What is the difference between S235JR and S275JR?
S235JR is used in less demanding applications, such as general construction, lightweight structures, and components where lower strength is sufficient (e.g., beams, columns, and frames). S275JR is preferred for applications requiring higher strength, such as heavier structural components, bridges, or machinery parts.