ST52 Seamless Pipe: Dimensions, Uses & Stockist
The ST52 seamless pipe is a trusted material in many heavy-duty systems due to its strength, reliability, and high load-bearing capacity. These pipes are manufactured out of high-grade carbon steel pipe, which has a smooth, uniform structure with no welded joints, making them suitable for high pressure and temperature. All industries use these pipes for construction, machinery, oil transport, and hydraulic applications due to their durability and accuracy in size. Its toughness and resistance to wear allow it to handle demanding environments with ease. This blog covers ST52 pipe dimensions, DIN 2391 ST52 standard details, applications in key sectors, chemical makeup, welding and tolerances, and stock availability. In short, this blog explains ST52 grade basics, size tables, and uses in different industries. It also highlights welding, tolerances, and material composition for proper selection.
What is ST52 Seamless Pipe?
The ST52 seamless pipe is a high-strength, low-alloy structural steel pipe. It is primarily defined by the German standard DIN 1629/EN 10297-1. The “seamless” manufacturing process means the pipe has no welded seam, which significantly raises its pressure-retaining capabilities and uniformity throughout the structure. One of the most outstanding features of this pipe is its mechanical properties, mainly a high tensile and yield strength in conjunction with adequate ductility. It also enables the pipe to withstand extremely high operational pressures and mechanical stress without deformation or failure. Its critical nature makes it particularly reliable for essential applications requiring safety and longevity.
Dimension Table (DIN 2391)
The standard dimensions of an ST52 seamless pipe are specified according to DIN 2391, which covers seamless precision steel tubes. The standard provides for tight tolerances on the outside diameter (OD) and wall thickness, a factor highly critical in hydraulic cylinder applications. The following table provides common dimensional data.
| Outside Diameter (OD) (mm) | Wall Thickness (WT) (mm) | Inside Diameter (ID) (mm) |
| 10 | 1 | 8 |
| 20 | 2 | 16 |
| 30 | 3 | 24 |
| 50 | 5 | 40 |
| 80 | 8 | 64 |
| 100 | 10 | 80 |
| 150 | 15 | 120 |
Applications of ST52 Seamless Pipe
The exceptional strength and fatigue resistance of ST52 pipe make it indispensable in many heavy industries. Its capacity to work under extreme stress and pressure is essential due to its adaptability.
- Hydraulic and pneumatic systems: They commonly use ST52 in hydraulic cylinders and lines. Its exceptional strength withstands high pressures in these systems. The seamless pipes have a smooth inside surface, which reduces the friction.
- Oil & Gas Industry: St52 is widely used in the oil and gas industry, including as transportation pipelines and downhole equipment. The material’s strong yield strength and reliability are important for harsh environmental conditions.
- Construction and Infrastructure: It is used as a structural component in heavy machines, cranes, and offshore structures. The pipe’s toughness offers the required load-bearing capacity.
- Automotive and Manufacturing: ST52 is found in high-pressure fuel lines and precision parts for industrial machinery. Its consistency and tight tolerances meet strict manufacturing requirements.
Chemical Composition Table
The chemical composition of ST52 steel determines its strength, weldability, and other mechanical properties. This low carbon concentration enhances the alloying components, which contribute to its high performance. The percentiles listed below are some common maximum percentages depending on the appropriate standards.
| Element | Percentage (%) Max |
| Carbon (C) | 0.22 |
| Silicon (Si) | 0.55 |
| Manganese (Mn) | 1.60 |
| Phosphorus (P) | 0.035 |
| Sulfur (S) | 0.035 |
| Vanadium (V) | 0.10 |
| Niobium (Nb) | 0.09 |
| Titanium (Ti) | 0.15 |
Welding/Tolerances
One of the most significant advantages of ST52 steel is its outstanding weldability; however, certain measures must be taken. Its tolerances, particularly for precision applications, are strictly governed by standards such as DIN 2391.
- Welding Properties: ST52 can be easily welded using common welding methods like shielded metal arc welding (SMAW) or gas metal arc welding (GMAW). Preheating is generally not required for sections up to 12 mm thick. For thicker sections, mild preheating can prevent cold cracking. Post-weld heat treatment may be necessary for stress relief in highly critical applications.
- Tolerances: The dimensional tolerances are crucial, especially for hydraulic applications. For precision seamless tubes, DIN 2391 specifies tight limits on the outside diameter and wall thickness. For instance, the diameter tolerance for a pipe can be as fine as $\pm 0.05$ mm, and the wall thickness tolerance is often $\pm 10\%$ or better, ensuring proper fitting and sealing in demanding systems.
Rexton Steel & Alloys provides reliable, high-quality ST52 seamless pipes. To fulfil the project deadlines, we maintain a large inventory of different ST52 pipe dimensions on hand. Contact Rexton Steel & Alloys immediately for a quote or to find out about our current stock availability.
FAQ’s
What are the dimensions of ST52 seamless pipes?
The common dimensions for St52 pipes are usually governed by specifications like DIN 2391 St52, which are available in a wide array of outside diameters and wall thicknesses. These dimensions are for precision use, normally featuring tight tolerances over OD and wall thickness.
Why are ST52 pipes used in the oil & gas industries?
Applications for St52 in oil and gas rely on its high strength and durability, which are important for safe operation. High yield strength possessed by the material, with the rating of 355 MPa, enables it to sustain high internal pressures and mechanical stress found in drilling and transportation.
What is the chemical composition of ST52?
The chemical composition of ST52 is low-alloy, and with a carbon content of about 0.22 percent as the maximum, it contains manganese (Mn) and silicon (Si) that contribute to its mechanical strength and good welding properties.
What are ST52 welding properties & tolerances?
ST52 has good weldability by normal techniques; preheating is recommended for thicker sections. The tolerances, especially for precision tubes, are very small to ensure dimensional accuracy as per DIN 2391.
What is the ST52 yield strength spec?
The minimum yield strength for ST52 is 355 MPa. This high yield strength of 355 MPa is an important mechanical feature, which allows the pipe to withstand heavy loads and high pressures without permanent deformation.