Precision carbon steel tubes are cold-drawn or cold-rolled seamless and welded steel tubes engineered for tight dimensional tolerances, smooth surface finishes, and consistent mechanical properties. Designed for fluid power systems and high-stress mechanical applications, these tubes minimize internal machining time and guarantee structural integrity under high pressure.
Specifications
|
Parameter |
Technical Standard / Range |
|
Size Range |
Outer Diameter (OD): 6mm – 355mm; Wall Thickness (WT): 0.5mm – 35mm |
|
Common Steel Grades |
SAE 1020, SAE 1045, E355, ST52, E235, CK45, 20#, 45# |
|
Executive Standards |
EN 10305-1, EN 10305-2, ASTM A519, DIN 2391, JIS G3445 |
|
Delivery Conditions |
+C (Cold worked / hard), +LC (Cold worked / soft), +SR (Stress relieved), +A (Annealed), +N (Normalized) |
|
Length Options |
Fixed lengths (3m–12m) or random lengths per purchase order |
Material & Manufacturing Process
Raw Material Control: Sourced strictly from certified primary steel mills with controlled chemistry (low sulfur and phosphorus limits) to ensure predictable weldability and tensile response.
Multi-Pass Cold Drawing: Processed on multi-strand cold drawing benches to achieve precise wall thickness reduction and outer/inner diameter control up to ±0.05 mm.
Bright Annealing (Controlled Atmosphere): Roller-hearth furnaces utilizing protective nitrogen-hydrogen atmospheres prevent high-temperature scaling, delivering a clean, oxide-free surface internally and externally.
Precision Straightening & Cutting: Multi-roller straightening mills control straightness within 1.0 mm/m, followed by burr-free rotary cutting.
Quality Inspection & Traceability
100% Eddy Current Testing:
Inline electromagnetic testing inspects the entire tube length for longitudinal surface and subsurface defects.
Continuous Dimensional Monitoring:
Laser micrometers track OD, ID, and wall thickness variations in real-time during production runs.
Destructive Testing Lab:
In-house mechanical testing verifies tensile strength, yield strength, elongation, and flattening/flaring performance per heat lot.
Full Lot Traceability:
Every tube bundle is stamped and tagged with unique heat numbers, fully traceable to the EN 10204 3.1 Mill Test Certificate (MTC).
Typical Applications
Hydraulic & Pneumatic Cylinders: Honed and roller-burnished tubes providing mirror-like inner surfaces for seamless fluid power sealing.
Automotive Drivetrains & Steering: Precision tubing utilized in propeller shafts, steering columns, axle housings, and fuel injection lines.
Heavy Machinery & Industrial Equipment: Used for precision roller bearings, robotic structural arms, textile spindles, and high-pressure fluid transfer lines.
Customization & Supply Chain
Dimensional Customization: Non-standard outer diameters, odd wall thicknesses, and special cut-to-length tolerances engineered upon request.
Surface Preservation: Anti-rust corrosion-inhibiting oil coating, phosphating, or customized passivation treatments.
Export-Grade Packaging: Plastic protective caps fitted on both ends, bundled with woven belts, and secured in heavy-duty wooden crates or steel-framed packages to survive ocean transit.
Manufacturing Footprint: 6 dedicated cold-drawing production lines delivering a stable monthly output of 5,000 metric tons.
FAQ
Q: What steel grades do you typically recommend for hydraulic cylinder manufacturing?
A: We frequently supply E355 (+SR or +N condition) and SAE 1045 / CK45 grades. They offer high yield strength and a homogeneous micro-structure suitable for subsequent honing and chrome plating.
Q: What standard dimensional tolerances do your precision tubes adhere to?
A: Production strictly complies with EN 10305-1 (e.g., ±0.08 mm for standard OD). Tighter tolerances can be mutually agreed upon during contract review.
Q: Can you accommodate third-party pre-shipment inspections?
A: Yes. We regularly facilitate inspections by recognized agencies such as SGS, BV, TUV, and Lloyd's Register at the buyer's expense.
Q: What is the standard minimum order quantity (MOQ) for non-standard custom dimensions?
A: For non-standard sizes not in our regular rolling schedule, the MOQ typically starts at 3 to 5 metric tons per size to accommodate tooling adjustments.
Q: How do you protect carbon steel tubes from oxidation during ocean freight?
A: Tubes are coated internally and externally with a high-grade rust-preventative oil, fitted with plastic end caps, and wrapped in moisture-resistant film prior to bundling.
Q: Which delivery condition is best suited for secondary machining operations?
A: The +SR (stress relieved) or +A (annealed) conditions are strongly recommended. These treatments minimize internal residual stresses, preventing distortion when parts are turned or milled.
Request a Quote
Submit your project requirements below to receive a direct quotation, complete with mill test certificate samples and lead times.
Outer Diameter (OD): [ ] mm / inches
Wall Thickness (WT): [ ] mm / inches
Steel Grade / Standard: [ ] (e.g., E355, ASTM A519, DIN 2391)
Delivery Condition: [ ] (e.g., +SR, +C, +A)
Target Quantity: [ ] Metric Tons / Meters
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