Home > Seamless Tube > DIN 2391 / EN 10305
Inox Steel India is a leading manufacturer and global supplier of Precision Steel Tubes and Hydraulic Tubes manufactured as per DIN 2391 and EN 10305 standards, covering ST35 (E235) and ST52 (E355) grades.
These tubes are widely used in high-pressure hydraulic systems, automotive components, shock absorbers, heavy machinery, instrumentation lines, and precision-engineered assemblies.
We supply to industries across GCC, Middle East, Europe, Africa, North America, and South America, with stock maintained in NBK (Normalized), BK (Cold Finished), BKW, and BKS conditions to meet diverse mechanical and dimensional requirements.
With ISO 9001, EN 10204 3.1, PED and strict metallurgical controls, our seamless cold-drawn steel tubes deliver exceptional dimensional accuracy, smooth inner bore, high pressure resistance, and superior fatigue performance.
Precision steel tubes are seamless cold-drawn tubes manufactured with extremely tight tolerances, superior surface finish, and high structural integrity.
They are essential for systems where:
Compared to standard seamless pipes, precision tubes are engineered specifically for:
Hot Rolled Tube Production
Steel billets are heated and pierced to form hollows used for precision cold drawing.
Cold Drawing
Heat Treatment
Phosphating / Oiling
Provides corrosion protection and internal lubrication.
Final Finishing & Straightening
Mandatory Testing
ST35 (E235)
ST52 (E355)
| Application | Service Condition | Industries |
| Automotive Fuel Lines | Moderate pressure | Automotive |
| Hydraulic System Lines | Medium pressure | Machinery |
| Shock Absorbers | Smooth piston movement | Automotive |
| Instrumentation Tubes | Precision OD/ID | Oil & Gas |
| Pneumatic Lines | High-cycle | Automation |
| Application | Pressure / Load | Industries |
| Hydraulic Cylinder Tubes | High pressure | Construction |
| Telescopic Cylinder Tubes | Cyclic load | Earthmoving |
| Heavy Duty Lifting Equipment | Dynamic load | Material Handling |
| Steering System Tubes | High tensile | Automotive |
| Mechanical & Structural Tubes | Heavy impact | Engineering |
| NPS | OD (mm) | Wall (mm) | Approx. Weight (kg/m) |
| ½″ | 12 | 1.5 | 1.10 |
| ¾″ | 19 | 2.0 | 2.20 |
| 1″ | 25 | 2.5 | 3.60 |
| 1½″ | 38 | 3.0 | 6.80 |
| 2″ | 50 | 3.5 | 9.80 |
| 2½″ | 63 | 4.0 | 13.20 |
| 3″ | 76 | 5.0 | 19.80 |
| Grade | Condition | INR/kg | USD/kg | Typical Use |
| ST35 (E235) | NBK | ₹ 85 – ₹ 135 | $1.10 – $1.65 | Automotive |
| ST35 (E235) | BK | ₹ 95 – ₹ 150 | $1.25 – $1.90 | Fuel Lines |
| ST52 (E355) | NBK | ₹ 105 – ₹ 165 | $1.35 – $2.10 | Hydraulic Cylinders |
| ST52 (E355) | BK | ₹ 120 – ₹ 185 | $1.60 – $2.35 | Heavy Machinery |
ST52 (E355) is significantly stronger with higher tensile (490–630 MPa) and yield (≥355 MPa) strength. Yes. ST52 is the industry standard for high-pressure hydraulic cylinder barrels. NBK is best for bending and forming operations. The HSN code is 7304.31.90. Yes — all tubes can be supplied with 3.1 or 3.2 certification. Yes, we export regularly to UAE, Oman, Saudi Arabia, Germany, Italy, Poland, and the UK. Which is stronger — ST35 or ST52?
Are ST52 tubes suitable for hydraulic cylinders?
What delivery condition is recommended for bending?
What is the HSN Code for precision steel tubes?
Do you supply tubes with EN 10204 3.1 certification?
Do you export to the Middle East and Europe?