DIN 2391 Precision Seamless Steel Tubes
- OD: 4 – 260mm
- WT: 0.5 – 25mm
- Grade: St35, St45, St52
DIN 2391 Precision Seamless Steel Tubes
DIN 2391 Precision Seamless Steel Tubes are high-quality tubes manufactured to the exacting standards of the German Institute for Standardization (DIN). Known for their superior dimensional accuracy and smooth surface finish, these tubes are ideal for applications requiring high precision and reliability. Commonly used in the automotive, mechanical engineering, and hydraulic industries, DIN 2391 tubes provide exceptional strength, durability, and corrosion resistance. Their seamless construction ensures uniformity and eliminates weak points, making them suitable for high-pressure and high-temperature environments. Available in various grades and dimensions, these tubes are engineered to meet the stringent demands of modern industrial applications.
Chemical Composition of DIN 2391 Precision Seamless Steel Tubes
| Element | Grade St 35 (1.0308) | Grade St 45 (1.0408) | Grade St 52 (1.0580) |
| Carbon (C) | ≤ 0.17% | ≤ 0.21% | ≤ 0.22% |
| Manganese (Mn) | ≤ 0.40% | ≤ 0.55% | ≤ 1.60% |
| Phosphorus (P) | ≤ 0.025% | ≤ 0.025% | ≤ 0.025% |
| Sulfur (S) | ≤ 0.025% | ≤ 0.025% | ≤ 0.025% |
Mechanical Properties of DIN 2391 Precision Seamless Steel Tubes
| Grade | Delivery Condition | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (A5, %) |
| St 35 (1.0308) | BK (Cold finished/hard) | ≥ 600 | – | – |
| BKW (Cold finished/soft) | 400 – 480 | ≥ 235 | ≥ 25 | |
| BKS (Cold finished/stress relieved) | 440 – 590 | ≥ 315 | ≥ 22 | |
| GBK (Annealed) | 340 – 470 | ≥ 235 | ≥ 25 | |
| NBK (Normalized) | 340 – 470 | ≥ 235 | ≥ 25 | |
| St 45 (1.0408) | BK (Cold finished/hard) | ≥ 700 | – | – |
| BKW (Cold finished/soft) | 500 – 640 | ≥ 275 | ≥ 21 | |
| BKS (Cold finished/stress relieved) | 540 – 690 | ≥ 375 | ≥ 20 | |
| GBK (Annealed) | 420 – 580 | ≥ 275 | ≥ 21 | |
| NBK (Normalized) | 420 – 580 | ≥ 275 | ≥ 21 | |
| St 52 (1.0580) | BK (Cold finished/hard) | ≥ 840 | – | – |
| BKW (Cold finished/soft) | 600 – 750 | ≥ 355 | ≥ 16 | |
| BKS (Cold finished/stress relieved) | 640 – 790 | ≥ 450 | ≥ 14 | |
| GBK (Annealed) | 490 – 630 | ≥ 355 | ≥ 20 | |
| NBK (Normalized) | 490 – 630 | ≥ 355 | ≥ 22 |
Specifications
| Standard | DIN 2391 Precision Seamless Steel Tubes |
| Steel Grade/Material | St35(1.0308), St45(1.0408), St52(1.0580) |
| Outside Diameter (OD) | 4 – 260mm |
| Wall Thickness (WT) | 0.5 – 25mm |
| Length | 500 – 3000mm |
| End | Plain Ends |
| Packing | Typically packed in protective wrapping, plastic end caps, and bundled with straps or placed in wooden or plastic crates, often palletized and labeled to ensure safe transportation and storage. |
| Section Shape | Round |
| Technique | Seamless Cold-Drawn |
| Delivery Conditions | BK (Cold finished/hard): No heat treatment after the final cold drawing process. High tensile strength but low ductility. BKW (Cold finished/soft): After the final cold drawing process, the tubes are annealed in a controlled atmosphere to get a suitable metallurgical condition for machining and/or forming. BKS (Cold finished/stress relieved): After the final cold drawing process, the tubes are stress-relief annealed in a controlled atmosphere to reduce the internal stresses resulting from the cold drawing process. GBK (Annealed): After the final cold drawing process, the tubes are annealed in a controlled atmosphere to obtain the desired microstructure. NBK (Normalized): After the final cold drawing process, the tubes are normalized by heating to a temperature above the transformation range followed by air cooling to achieve a normalized condition. |
| Place of Origin | Made in China |
| MOQ | 3 Ton/Size |
| Transportation | Land transportation by truck or train, sea transportation by container ship or bulk ship. |
Applications of DIN 2391 Precision Seamless Steel Tubes
Automotive Industry
Fuel Injection Systems: Used in fuel injection systems due to their high precision and ability to withstand high pressure.
Hydraulic Lines: Utilized in hydraulic systems and power steering lines, where high strength and precision are required.
Brake Lines: Employed in braking systems for their reliability and durability.
Mechanical Engineering
Hydraulic and Pneumatic Cylinders: Ideal for hydraulic and pneumatic cylinder applications because of their high dimensional accuracy and smooth surface finish.
Machinery Parts: Used for manufacturing precision machinery parts such as shafts, axles, and mechanical components.
Aerospace Industry
Aircraft Components: Used in the production of aircraft components that require high strength, reliability, and precision.
Hydraulic Systems: Essential for hydraulic systems in aircraft for their ability to withstand high pressure and provide accurate control.
Medical Equipment
Medical Devices: Used in the manufacture of medical devices and equipment that require high precision, such as surgical instruments and diagnostic equipment.
Implants: Utilized in making medical implants due to their biocompatibility and precise dimensions.
Oil and Gas Industry
Control Lines: Used in control lines for oil and gas exploration and production, where high pressure and corrosion resistance are crucial.
Instrumentation Tubing: Employed in instrumentation and measurement systems in the oil and gas sector for their high precision and reliability.
Industrial Equipment
Heat Exchangers: Used in heat exchangers and condensers for their excellent thermal conductivity and mechanical properties.
Boiler Tubes: Utilized in boiler systems due to their ability to withstand high pressure and temperature.
Construction
Structural Applications: Used in construction for structural applications requiring high strength and precise dimensions.
Scaffolding: Employed in scaffolding systems where strength, durability, and safety are paramount.
Energy Sector
Power Plants: Used in power plants for various applications such as steam generation and fluid transfer due to their ability to withstand high pressure and temperature.
Renewable Energy: Employed in renewable energy systems, such as wind and solar energy, for structural and mechanical components.
Marine Industry
Shipbuilding: Used in shipbuilding for various applications including hydraulic systems, structural components, and engine parts due to their corrosion resistance and high strength.
Food and Beverage Industry
Hygienic Applications: Used in the food and beverage industry for hygienic applications where precision, cleanliness, and corrosion resistance are essential.
