1. **What is EN 10219 material?**
EN 10219 is a European Standard that specifies the technical delivery conditions for **cold-formed welded structural hollow sections** (like square, rectangular, and circular tubes) made from non-alloy and fine grain steels. These sections are used in construction and structural engineering applications where high strength and good weldability are required. The standard covers dimensions, tolerances, mechanical properties, and chemical composition.
2. **What is the difference between EN 10210 and EN 10219?**
The key difference lies in the **manufacturing process**:
* **EN 10210** covers **hot-finished** welded structural hollow sections. The forming and welding happen at high temperatures (typically above the recrystallization temperature of the steel).
* **EN 10219** covers **cold-formed** welded structural hollow sections. The forming happens at or near room temperature, followed by welding. The cold-forming process generally results in tighter dimensional tolerances compared to hot-finished sections.
3. **What size is EN 10219?**
EN 10219 **itself is a material specification standard, not a dimensional standard**. It does not define specific sizes. The dimensional ranges (outer dimensions, wall thicknesses) for the hollow sections (Square - SHS, Rectangular - RHS, Circular - CHS) covered by EN 10219 are specified in a separate part of the standard: **EN 10219-2: "Part 2: Tolerances, dimensions and sectional properties"**. You need to refer to EN 10219-2 to find the available sizes and their tolerances.
4. **What is EN 10219 S355J2H equivalent to?**
The designation "S355J2H" within EN 10219 refers to a specific **steel grade** intended for hollow sections. Finding an exact equivalent depends on the context (which standard system you need equivalence in). Common equivalents include:
* **ASTM (USA):** ASTM A500 Grade C is frequently considered the closest equivalent for structural tubing, particularly regarding minimum yield strength. However, there are differences in chemical composition requirements and specified impact test temperatures.
* **ISO:** ISO 630-5:2021 designates structural steels for hollow sections. S355J2H maps directly to **ISO 630-5: E355K2H**.
* **General Performance:** Steel with a minimum yield strength of 355 MPa (or 50 ksi), good weldability, and specified impact energy at -20°C (indicated by "J2").
5. **What is the Chinese equivalent of S355J2H?**
The closest Chinese equivalent standard and grade for S355J2H (cold-formed hollow sections) is found in **GB/T 6728** (Standard for cold-formed welded structural hollow sections). The equivalent grade is typically **Q355B**.
* **Q355:** Indicates the minimum yield strength is 355 MPa.
* **B:** Indicates the quality grade, specifying impact energy requirements at +20°C (which is less stringent than the -20°C requirement of the "J2" in S355J2H).
**Important Note:** While Q355B is the standard equivalent, the "J2" impact requirement at -20°C in S355J2H is more demanding than the standard impact requirement for Q355B at +20°C. For applications requiring low-temperature toughness, specifying the exact impact test temperature requirement is crucial, regardless of the nominal grade equivalence.
