Hot-rolled mechanical steel tubes are engineered for heavy structural components, hydraulic systems, and industrial machinery where high strength, uniform grain structure, and reliable machinability are required. Produced via controlled hot-rolling processes, these tubes deliver optimal mechanical properties with minimal internal residual stress, reducing initial machining time and material waste compared to solid bars.
Production Range: OD 30 mm – 400 mm; WT 3 mm – 50 mm.
Delivery Conditions: As-rolled (+AR), Normalized (+N).
Core Advantage: Balanced strength-to-weight ratio and predictable response to subsequent thermal processing or precision machining.
Specifications
|
Parameter |
Specification Range |
Compliant Standards |
|
Outer Diameter (OD) |
30 mm – 400 mm |
ASTM A519, EN 10305-2, DIN 2391 |
|
Wall Thickness (WT) |
3 mm – 50 mm |
ASTM A519, ISO 2938 |
|
Standard Lengths |
5,800 mm – 12,000 mm (Cut-to-length available) |
Mill Standard / Custom |
|
Steel Grades |
SAE 1020, SAE 1045, E355, ST52, 20MnV, 4140 |
ASTM, EN/DIN, JIS |
|
Surface Finish |
Hot-rolled finish, optional scale-removed / shot-blasted |
Commercial Standard |
Material & Manufacturing
Manufactured from primary electric arc furnace (EAF) and basic oxygen furnace (BOF) steel billets, ensuring low non-metallic inclusion levels and consistent chemical composition.
Hot Piercing & Rolling Mill: Billets are heated to 1250°C and processed through continuous mandrel mills to strictly control wall thickness eccentricity and concentricity.
Thermal Treatment: Inline or batch normalizing furnaces refine the ferrite-pearlite grain structure and relieve internal residual stresses prior to delivery or machining.
Process Control: Automated temperature regulation during rolling secures predictable yield and tensile strengths across individual production lots.
Quality Inspection
Every production lot undergoes strict metallurgical and dimensional verification. Mill Test Certificates (MTC) conforming to EN 10204 3.1 are supplied with every shipment.
Dimensional Monitoring: Continuous laser OD/ID measurement and ultrasonic wall thickness gauges operate directly along the rolling line.
Non-Destructive Testing (NDT): Eddy current or magnetic particle inspection (MPI) for surface and subsurface defect detection per ASTM E309 / EN 10246.
Mechanical Verification: Tensile testing, yield strength verification, elongation measurement, and Charpy V-notch impact testing conducted per lot.
Chemical Analysis: Spectrometric ladle and product analysis verifying carbon, manganese, silicon, sulfur, and phosphorus limits.
Third-Party Inspection: Accommodates inspections by SGS, BV, TÜV, or Lloyd's Register upon request.
Applications
Engineered for load-bearing and functional components across heavy industrial sectors:
Fluid Power: Hydraulic and pneumatic cylinder barrels requiring tight inner diameter tolerances.
Automotive: Drive shafts, axle tubes, steering columns, and structural suspension components.
Machinery: Roller bearings, conveyor rollers, crane booms, and heavy-duty agricultural implement frames.
Energy: Wind turbine internal structural sleeves and oilfield auxiliary equipment parts.
Customization & Supply
Dimensional Customization:
Non-standard OD and WT combinations rolled to project-specific engineering drawings.
Length Options:
Exact fixed lengths (tolerance ± 2 mm) or random lengths.
End Finishing:
Plain square cut, deburred, or bevel-prepped for automated welding.
Packaging:
Bundled with steel strapping, wrapped in moisture-resistant woven fabric, equipped with plastic end caps to prevent transit damage. Minimum Order Quantity (MOQ) depends on steel grade and dimensions.
FAQ
Q: What is the difference between hot-rolled mechanical tubing and cold-drawn tubing?
A: Hot-rolled tubes feature a higher starting thickness range, larger scale finish, and effective high-temperature stress relief, making them cost-effective for heavy machining. Cold-drawn tubes offer tighter dimensional tolerances, smoother surface finish, and higher yield strength due to cold work hardening.
Q: Can these tubes be supplied with specific mechanical properties for heat treatment?
A: Yes. Grades such as SAE 1045 or 4140 can be supplied in normalized or quenched-and-tempered conditions tailored for subsequent induction hardening or carbonitriding.
Q: What tolerance standards do you follow for outer diameter and wall thickness?
A: Tolerances adhere strictly to ASTM A519 or EN 10305 standards depending on the selected grade and sizing method. Specific project tolerances can be agreed upon prior to production.
Q: Do you provide third-party inspection (TPI) services?
A: Yes. We regularly accommodate inspection by SGS, BV, TÜV, or Lloyd's Register designated by the buyer prior to final release.
Q: What is the standard mill lead time for bulk orders?
A: Standard production lead time ranges from 30 to 45 days, depending on rolling schedules, steel grade availability, and required testing protocols.
Q: What documentation accompanies each shipment?
A: Each shipment includes a Bill of Lading, Packing List, Commercial Invoice, and an EN 10204 3.1 Mill Test Certificate detailing chemical composition and mechanical test results.
Request a Quote
To receive a formal quotation, please provide the following parameters:
• Steel Grade (or application requirement)
• Outer Diameter (OD) and Wall Thickness (WT)
• Required Length (Fixed or Random)
• Order Quantity (Tons or Pieces)
• Target Port of Destination / Incoterms (FOB / CIF)
[Submit Your RFQ / Contact Our Engineering Sales Team]
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