DIN 2391 ST 44 seamless precision steel tubes are cold-drawn, low-carbon steel tubes to meet the requirements of DIN 2391 Part 2 and have an EN 10305-1 E235 equivalent grade. These tubes are manufactured with OD tolerances of ±0.30 mm to ensure consistent bore geometry for hydraulic cylinder bore machining, pneumatic actuator bodies, and close-tolerance mechanical assemblies, and have a yield strength of ≥ 235 MPa. They are available in OD 4–120 mm, bright annealed (BA), annealed and pickled (AP) or phosphated finish depending on the downstream processing requirements, with wall thickness 0.5–12.5 mm. ST 44 tubes are highly regarded for their precision, strength, and suitability for hydraulic applications, automotive components, engineering equipment, and other high-precision mechanical parts. They come in many sizes, wall thicknesses and custom lengths, and can be provided to suit a variety of industrial requirements. We manufacture and supply at usapipingsolution premium quality DIN 2391 ST 44 Seamless Precision Steel Tubes with the best raw material, to ensure it is reliable in performance, durable in life and meet the international quality standard.
Specifications of DIN 2391 ST 44 Seamless Precision Steel Tubes
| Category | Specification Details |
|---|---|
| Seamless Pipe Size | 4 mm to 219 mm (Wall Thickness: 0.5 mm to 20 mm) |
| Welded / EFW Pipe Size | 5.0 mm to 1219.2 mm |
| Seamless Tube Size | 3.35 mm OD to 101.6 mm OD |
| Welded Tube Size | 6.35 mm OD to 152 mm OD |
| Tube Wall Thickness (LTCS) | 0.020” to 0.220” (Special wall thicknesses available) |
| Swg & Bwg Gauges | 10 Swg, 12 Swg, 14 Swg, 16 Swg, 18 Swg, 20 Swg |
| Pipe Schedules | SCH5, SCH10, SCH10S, SCH20, SCh20, SCH40, SCH40S, STD, SCH80, XS, SCH60, SCH120, SCH140, SCH160, XXS |
| Types Available | Seamless, Welded, ERW, EFW, Fabricated, ‘U’ bent, Hollow, Hydraulic, LSAW, Boiler, Straight Tube, Tube Coil |
| Forms Available | Round, Rectangular, Square, Hydraulic, ‘U’ bent, Hollow, LSAW, Boiler, Straight Pipe, Clad Pipe |
| Ends Finish | Plain End, Beveled End, Treaded Pipe & Tube |
| Surface Finish | Polished, AP (Annealed & Pickled), BA (Bright & Annealed), MF |
| Lengths | Single Random, Double Random, Standard, and Cut lengths |
| Standard Marking | Standard, Grade, OD, Thickness, Length, Heat No. (or per customer request) |
| Applications | Oil, Gas, Fluid, Boiler, and Heat Exchanger Pipes & Tubes |
| Value Added Services | Draw & Expansion (per required size/length), Electro & Commercial Polishing, Annealed & Pickled Bending, Machining, etc. |
Different Types of DIN 2391 ST 44 Seamless Steel Tubes
DIN 2609 Grade St 44-0 Equivalent Grades
| DIN 2391 | EN 10305-1 | ISO | BS | Approximate ASTM |
|---|---|---|---|---|
| ST 44 | E235 | ISO 3304 / 3305 (Class 1/2) | CFS 3 (BS 3601 family) | ASTM A519 Grade 1020 (closest; not a direct equivalent) |
Wall Thickness Chart of DIN 2391 ST 44 Seamless Tubes
| Execution | Size Range | OD Tolerance | Wall Tolerance |
|---|---|---|---|
| Hot-rolled Tube | OD – 80 mm / OD > 80 mm / Wall < 12 mm / Wall ≥ 12 mm | ± 0.4 mm / ± 0.5% of OD | ± 0.7 mm / ± (5% × wall thickness + 0.1 mm) |
| Hot-rolled peeled tube | All sizes / Wall < 12 mm / Wall ≥ 12 mm | +0.25 / −0 mm | ± 0.8 mm / ± (5% × wall thickness + 0.2 mm) |
| Cold Worked tube (cold-rolled or cold-drawn) | OD < 40 mm / OD 40–80 mm / OD > 80 mm / Wall < 6 mm / Wall 6–8 mm / Wall > 8 mm | +0.30 / −0 mm* / +0.35 / −0 mm* / +0.40 / −0 mm* | ± 0.30 mm / ± 0.35 mm / ± 0.40 mm |
Dimensional Tolerances of DIN 2609 Grade St 44-0 Seamless Tube
| Component Length (mm) | OD 30–100 mm | OD 100–254 mm |
|---|---|---|
| 10–100 | +1.0 / −0 | +2.0 / −0 |
| 100–600 | +2.0 / −0 | +3.0 / −0 |
| 600–1200 | +3.0 / −0 | +4.0 / −0 |
| 1200–5000 | +5.0 / −0 | +6.0 / −0 |
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Applications and Industries of DIN 2609 Grade St 44-0 Seamless Tube
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Frequently Asked Questions
What is DIN 2391 ST 44 seamless precision steel tube?
DIN 2391 ST 44 is a seamless carbon steel precision tube known for its high dimensional accuracy, smooth surface finish, and good mechanical strength.
What is the difference between ST 44 and ST 52 tubes?
ST 52 tubes have higher tensile and yield strength than ST 44 tubes, making them suitable for more demanding structural and hydraulic applications.
Is DIN 2391 ST 44 a carbon steel grade?
Yes, DIN 2391 ST 44 is a low-carbon steel grade designed for precision tubing and engineering applications.
What are DIN 2391 ST 44 seamless precision steel tubes used for?
They are commonly used in hydraulic systems, pneumatic equipment, automotive components, machinery, and precision engineering applications.
Are ST 44 tubes suitable for hydraulic applications?
Yes, ST 44 seamless precision tubes are widely used in hydraulic systems due to their strength, accuracy, and pressure-handling capabilities.
Can DIN 2391 ST 44 tubes be used in pneumatic systems?
Yes, their smooth internal surface and precise dimensions make them suitable for pneumatic cylinders and air-pressure systems.
Which industries use DIN 2391 ST 44 seamless tubes?
These tubes are used in the automotive, hydraulic equipment, mechanical engineering, construction, manufacturing, and industrial machinery industries.
Mill-certified stock. EN 10305-1 E235 compliance. OD 4 to 120 mm. Full MTR documentation.
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