
DIN 1615 St33 St37 St42 St34.2 St37.2 Round Structural Pipe Welded Circular Unalloyed Steel Tubes
Material Specification
DIN 1615 standard specifies the requirements for welded circular unalloyed steel tubes used for structural purposes. These pipes are commonly used in construction and engineering projects due to their strength, durability, and versatility. The standard covers various steel grades, including St33, St37, St42, St34.2, and St37.2, each offering distinct mechanical properties to suit different applications.
Key Features
- Versatility: Suitable for a wide range of structural applications.
- Durability: High resistance to wear and tear, ensuring long service life.
- Cost-Effective: Economical choice for structural projects.
- Weldability: Excellent welding properties, facilitating easy fabrication.
- Compliance: Meets international standards for structural steel pipes.
Chemical Composition
The chemical composition of these steel grades is crucial for determining their mechanical properties and suitability for specific applications. Below is a table presenting the typical chemical composition for these grades:
Element | St33 (%) | St37 (%) | St42 (%) | St34.2 (%) | St37.2 (%) |
C | ≤ 0.17 | ≤ 0.20 | ≤ 0.22 | ≤ 0.17 | ≤ 0.20 |
Mn | ≤ 1.40 | ≤ 1.40 | ≤ 1.40 | ≤ 1.40 | ≤ 1.40 |
P | ≤ 0.045 | ≤ 0.045 | ≤ 0.045 | ≤ 0.045 | ≤ 0.045 |
S | ≤ 0.045 | ≤ 0.045 | ≤ 0.045 | ≤ 0.045 | ≤ 0.045 |
Mechanical Properties
The mechanical properties of these steel grades define their performance under various conditions. The table below summarizes the typical mechanical properties:
Property | St33 | St37 | St42 | St34.2 | St37.2 |
Yield Strength (MPa) | ≥ 185 | ≥ 235 | ≥ 275 | ≥ 185 | ≥ 235 |
Tensile Strength (MPa) | 340-470 | 360-510 | 410-550 | 340-470 | 360-510 |
Elongation (%) | ≥ 25 | ≥ 24 | ≥ 22 | ≥ 25 | ≥ 24 |
Steel Grade
The steel grades covered under DIN 1615 include:
- St33: Known for its excellent ductility and weldability.
- St37: Offers a good balance of strength and ductility.
- St42: Provides higher strength, suitable for more demanding applications.
- St34.2: Similar to St33 but with slight variations in mechanical properties.
- St37.2: An enhanced version of St37 with improved mechanical characteristics.
Application
These steel tubes are widely used in:
- Construction of buildings and bridges
- Manufacturing of machinery and equipment
- Automotive industry for structural components
- Fabrication of frames and supports
- General engineering purposes
Possible Alternative Grades
Depending on the specific requirements of a project, alternative grades may be considered:
- EN 10219 S235JR: Offers similar mechanical properties and is commonly used in Europe.
- ASTM A500 Grade A/B: Widely used in North America, providing comparable strength and ductility.
- JIS G3444 STK400: A Japanese standard with similar applications and properties.





TORICH Group, an one-stop service provider of raw materials engaged in raw material production, R&D and
trade, has 30+ years of experience in the market, exported to 56 +countries, and won good reputation and
credibility among domestic and foreign customers.
The company's production plant covers an area of over 10,000 square meters, with an annual production
capacity of 50,000 tons of materials and a comprehensive trading and warehousing capacity of 100,000 tons, which can satisfy customers' personalized needs for raw materials in terms of diversity and timeliness.
The group holds shares in more than ten domestic production entities, whose main products include
seamless steel pipes ( carbon steel and stainless steel), welded pipes ( carbon steel and stainless steel), pipe fittings ( carbon steel and stainless steel), titanium (titanium tubes, titanium rods, titanium cakes, titanium plates, etc.), aluminum (aluminum tubes, aluminum rods, aluminum die casting, aluminum casting, CNC machining), and CNC deep processing of metal materials such as tubes, rods, and casting parts.
Over the past 30 years, the company has been gradually developing new technologies and materials to meet
the growing needs of customers and various diversified needs, exporting to more than 56 countries and still
increasing the number of exporting countries, aiming to help customers to solve the demand for raw materials, and to facilitate one-stop purchasing for customers.






Q: Are you trading company or manufacturer ?
A: manufacturer,also can do trading.
Q: How long is your delivery time?
A: Generally speaking,it is 10-15 days if the goods are in stock,or it is 30-40 days if the goods are not in stock, it is according to quantity.
Q: Do you provide samples? is it free or extra ?
A: Yes, we could offer the sample for free charge but need pay the cost of freight.
Q: What is your terms of payment ?
A: Payment<=2000USD, 100% in advance. Payment>=2000USD, 30% T/T in advance ,balance before shippment.
If you have another question, pls feel free to contact with me.