Hot-rolled carbon steel tubes and structural pipes provide high load-bearing capacity and dimensional stability for heavy machinery, construction frameworks, and fluid transport. Produced via continuous rolling or rotary piercing processes, these industrial steel tubes feature a uniform austenitic grain structure and strict adherence to ASTM, EN, and API standards. Designed for direct integration into engineered structures and pressure systems.
Specifications
|
Parameter |
Standard Range / Metric |
Standard Range / Imperial |
|
Outer Diameter (OD) |
21.3 mm - 610 mm |
0.84 in - 24 in |
|
Wall Thickness (WT) |
2.0 mm - 60 mm |
0.08 in - 2.36 in |
|
Length |
5.8 m - 12 m (Random or Fixed) |
19 ft - 40 ft |
|
Steel Grades |
ASTM A53 Gr. B, ASTM A500 Gr. B/C, EN 10210 S235JR/S355JOH, API 5L Gr. B |
|
|
Execution Standards |
ASTM A53 / A500 / A519, EN 10210 / EN 10219, API 5L |
Material & Manufacturing
Chemical Composition & Mechanical Properties (Representative Grades)
• ASTM A500 Grade B: Tensile Strength >= 400 MPa, Yield Strength >= 290 MPa, Elongation >= 23%.
• EN 10210 S355JOH: Tensile Strength 470 - 630 MPa, Yield Strength >= 355 MPa, Impact Energy >= 27 J at 20°C.
Mill Manufacturing & Rolling Process
• Billet Heating: Continuous casting steel billets are heated to 1250°C in automated walking-beam furnaces, ensuring homogeneous internal microstructure before hot deformation.
• Hot Rolling & Piercing: Rotary piercing mills transform solid billets into seamless hollow shells, followed by multi-stand stretch reducing mills to control outer diameter and wall thickness tolerances.
• Controlled Cooling Beds: Cooling rates are managed according to steel carbon equivalents to prevent internal stress and secure designated mechanical hardness.
Quality Inspection & Mill Compliance
Every production lot undergoes strict factory testing prior to release:
Dimensional Verification: Continuous laser gauges monitor outer diameter, wall thickness, and ovality across the entire tube length.
Non-Destructive Testing (NDT): 100% electromagnetic or ultrasonic testing (UT) performed in accordance with ASTM E214 and EN 10246-7 to detect longitudinal and transverse defects.
Destructive Testing: Tensile tests, flattening tests, and bend tests conducted per heat lot.
Certification: Each bundle ships with an EN 10204 3.1 Mill Test Certificate, providing full traceability of chemical heats and mechanical test results.
Applications
Structural Engineering: Building columns, bridge trusses, offshore platform frameworks, and solar panel mounting structures.
Heavy Industrial Machinery: Crane booms, excavator chassis frames, agricultural machinery components, and conveyor roller systems.
Fluid & Gas Transmission: Industrial piping lines for non-critical water, air, and low-pressure steam transport.
Automotive & Transport: Axle tubes, drive shaft components, and heavy truck chassis reinforcement.
Customization & Supply Chain
Mill Direct Production:
Bi-weekly rolling schedules support high-volume distribution and predictable mill-direct supply chains.
Dimensional Customization:
Non-standard outer diameters, specific wall thickness ratios, and tight-tolerance sizing available upon engineering review.
Precision Cutting:
Fixed-length cutting ranging from 3 m to 14 m with tight end tolerances (+5/-0 mm).
Surface & End Finishes:
Uncoated black finish, light anti-rust oil, external clear varnish, or shot blasting to Sa 2.5. Square-cut ends, beveled ends for welding, or threaded configurations.
Export Packaging:
Bundled with high-tensile steel strapping, plastic end protectors fitted to prevent transit damage, suitable for container or break-bulk shipping.
FAQ
Q: What compliance documentation is included with the shipment?
A: Every delivery includes an EN 10204 3.1 Mill Test Certificate verifying actual chemical analysis, mechanical property test data, and NDT compliance.
Q: Do you accommodate third-party inspection (TPI)?
A: Yes. Inspections by recognized agencies such as SGS, BV, TÜV, or Lloyd's Register can be accommodated prior to dispatch.
Q: What is the standard minimum order quantity (MOQ)?
A: For standard dimensions and grades, the MOQ is 5 metric tons per size. Custom rolling orders require a minimum of 10 metric tons per specification.
Q: Can you supply fixed-length structural steel tubes?
A: Yes, we provide precision cut-to-length services with strict length tolerances controlled within +5/-0 mm.
Q: How are tubes protected against ocean freight corrosion?
A: Tubes are treated with export-grade anti-rust oil or external varnish, and bundled securely with plastic end caps to prevent moisture ingress during maritime transport.
Q: What are the typical lead times for mill orders?
A: Ex-stock standard sizes ship within 7 to 14 days. Custom production orders require 30 to 45 days depending on current mill rolling cycles.
Request a Quote
To receive a formal commercial and technical proposal within 24 hours, please provide the following details:
1.Steel Standard & Grade (e.g., ASTM A500 Gr. B, EN 10210 S355JOH)
2.Outer Diameter (OD) & Wall Thickness (WT)
3.Length Requirements (Random or Fixed Length)
4.Total Quantity (Metric Tons or Pieces)
5.Surface Protection & End Finish Specifications
6.Destination Port / Delivery Location
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