S235 steel is a non-alloy structural steel, widely recognized and used as the workhorse of the construction and manufacturing industry. It is part of the family of structural steels specified by the European standard EN 10025-2.
| Symbol | Meaning | Explanation |
| S | Structural | Indicates that it is a structural steel. |
| 235 | Yield Strength | Represents the minimum guaranteed yield strength of $235\text{ MPa}$ ($\text{N/mm}^2$). Beyond this stress, the steel undergoes permanent (plastic) deformation |
| JR (ou J0, J2, etc.) | Impact Strength | Indicates guaranteed impact strength. JR means a minimum breaking energy of $27\text{ Joules (J)}$ at a test temperature of $+20^\circ\text{C}$ (Room) |
Key Technical Characteristics
| Property | Typical Value | Note |
| Yield Strength (Re) | $\ge 235\text{ MPa}$ | Guaranteed strength for structural applications. |
| Tensile Strength (Rm) | $360 – 510\text{ MPa}$ | Maximum force it can withstand before breaking. |
| Elongation at break (A) | $\ge 26\%$ | Indicates very good ductility, facilitating forming (bending, rolling). |
| Weldability | Excellent | Low carbon content allows welding without special precautions. |
| Machinability | Good to very good | Easy to work with (cut, drill, mill). |
S235 steel is the preferred choice for a wide range of applications where moderate structural performance and excellent cost-effectiveness are sought.
Main Applications
| Advantages | Limites |
| Economic | Low corrosion resistance (requires protection) |
| Excellent Weldability | Moderate mechanical strength |
The universal standard for metal construction.
S235 steel is the most widely used grade for locksmith work, industrial furniture, and light structural frames. As a non-alloy steel, it offers the best weldability on the market.
Reference Manufacturers: ArcelorMittal, ThyssenKrupp, Tata Steel.
USA (ASTM): A36 (the closest American standard).
Germany (DIN): St 37-2 (legacy designation still used by some engineering firms).
Japan (JIS): SS400.
Key Advantage: Highly competitive cost and ease of processing (bending, welding).