Inox Steel India is a leading manufacturer, exporter, and stockholder of DIN 2391 ST52 Precision Tubes — high-strength seamless tubes widely used in hydraulic systems, automotive components, machinery parts, structural engineering, and heavy-duty mechanical applications.
ST52 is a low-alloy, high-strength carbon steel grade known for its superior mechanical properties, excellent weldability, and high fatigue resistance.
Our cold drawn seamless (CDS) ST52 precision tubes offer very close dimensional tolerance, high strength-to-weight ratio, superior surface finish (OD & ID), excellent machinability, and straightness accuracy ideal for CNC machining.
DIN 2391 ST52 tubes are used where strength, precision, and durability are mandatory—especially in components exposed to high stress, dynamic loading, and pressure fluctuations.
Precision tubes must provide accurate OD & ID, fine tolerances for fittings & machining, high tensile and yield strength, smooth internal surface, and excellent bending & forming performance.
ST52 excels in all these areas due to its optimized carbon-manganese alloy chemistry.
| Application | Pressure | Use Case | Industries |
| Hydraulic Cylinders | High | Cylinder barrels, telescopic cylinders | Construction, Mining |
| Hydraulic Power Packs | High | Oil transfer lines | Industrial Machinery |
| Hydraulic Press Lines | High | High load-bearing | Steel, Forging |
| Steering Hydraulics | Medium–High | Marine steering lines | Marine |
| Component | Function | Industry |
| Drive Shafts | Torque transfer | Automotive |
| Stabilizer Tubes | Vibration handling | Commercial Vehicles |
| Axle Tubes | High load-bearing | Off-road Equipment |
| Chassis Tubes | Structural stability | EVs & OEMs |
| Application | Requirement | Industries |
| Mechanical Frameworks | High stiffness | Automation |
| Machine Tool Assemblies | Dimensional accuracy | CNC Units |
| Fabrication Components | Weldability | Structures |
| Precision Machining Parts | ID/OD accuracy | Engineering Firms |
| Parameter | Specification |
| Outside Diameter (OD) | 10 mm – 120 mm |
| Wall Thickness | 1 mm – 12.5 mm |
| Length | 6 m, 12 m, Custom Cut |
| Delivery Condition | NBK, BK, BKS |
| Surface Finish | Phosphated, Oiled, Bright, Pickled |
| Tube Type | Seamless, Cold Drawn Precision |
| Grade | Condition | INR/kg | USD/kg | Typical Use |
| ST52 | NBK | ₹120 – ₹170 | $1.50 – $2.20 | Cylinder barrels |
| ST52 | BK | ₹130 – ₹185 | $1.60 – $2.50 | Precision machining |
| ST52 | BKS | ₹140 – ₹195 | $1.75 – $2.65 | Honed tube production |
| Industry | Applications |
| Construction & Earthmoving | Hydraulic cylinders, stabilizers |
| Automotive | Drive shafts, axle tubes |
| Agricultural Machinery | Lift cylinders, steering tubes |
| Industrial Automation | Hydraulic lines, robotic arms |
| Machine Tools | CNC machining components |
| Mining & Material Handling | Heavy-duty hydraulic tubes |
Q1. What is ST52 precision tube used for?
Hydraulic cylinders, CNC machining & heavy-duty mechanical systems.
Q2. Difference between NBK, BK & BKS?
NBK: forming, BK: machining, BKS: honing.
Q3. Do you export ST52 tubes?
Yes, worldwide.