Stainless Steel Coil Tube with Precision Springback Compensation Bending
Wenzhou Jixing Metal Materials Co., Ltd supplies high-grade stainless steel coil tube engineered for precision bending and forming applications. Our coil tube products are specifically designed with springback compensation technology, ensuring dimensional accuracy and consistent geometry when tubes are formed into bends, elbows, and complex shapes during installation and maintenance workflows. Whether for heat exchangers, HVAC systems, or structural frameworks, our coil tube delivers reliable performance across a wide range of hardness states.
Product Overview
Stainless steel coil tube is supplied in continuous coil form, providing unmatched convenience for high-volume bending, coiling, and forming operations. Unlike straight-length tubing, coil tube eliminates butt welds and seam joints along the supply length, resulting in improved structural integrity, enhanced fluid flow characteristics, and reduced material waste. This makes it the preferred choice for applications requiring long, uninterrupted tube runs that are subsequently bent to specific configurations.
At Wenzhou Jixing Metal Materials Co., Ltd, we specialize in coil tube that has been engineered with a deep understanding of springback behavior. Springback — the elastic recovery of a tube after bending — is a critical variable that directly affects the final angle accuracy of formed bends. By categorizing our coil tube by hardness state and providing precise springback compensation data, we enable downstream fabricators and installers to achieve first-time-right dimensional accuracy without costly rework.
Material & Properties
Our stainless steel coil tube is manufactured from premium austenitic and duplex stainless steel grades, selected to balance formability, corrosion resistance, and mechanical strength. The material is processed through controlled rolling and annealing operations to achieve the desired hardness state, which directly governs the springback behavior during bending.
Available Grades
- 304 / 304L — General-purpose austenitic grade with excellent corrosion resistance and formability; widely used in food processing, chemical, and architectural applications.
- 316 / 316L — Molybdenum-enhanced austenitic grade offering superior resistance to pitting and crevice corrosion; ideal for marine, pharmaceutical, and chemical environments.
- 321 — Titanium-stabilized grade providing enhanced resistance to sensitization at elevated temperatures; suitable for heat exchangers and high-temperature service.
- 310S — High-temperature austenitic grade with outstanding oxidation resistance up to 1150°C; used in furnace components and thermal processing equipment.
- Duplex 2205 — High-strength duplex grade combining the best properties of austenitic and ferritic structures; delivers 2x the yield strength of 304 with excellent chloride resistance.
Key Material Properties
- Corrosion resistance in aggressive chemical and marine environments
- High strength-to-weight ratio with excellent fatigue performance
- Non-magnetic in annealed condition (austenitic grades)
- Hygienic, food-safe surface finish options available
- Weldability suitable for TIG, MIG, and orbital welding processes
- Operational temperature range from cryogenic to 1150°C depending on grade
Specifications
Coil Tube Dimensions
| Parameter | Range / Options |
|---|---|
| Outer Diameter (OD) | 3 mm – 168 mm |
| Wall Thickness | 0.3 mm – 6.0 mm | Coil Length | Up to 120 m per coil (custom lengths available) |
| Coil Weight | Up to 2,500 kg per coil |
| Bending Radius | 1D – 10D (based on tube OD) |
| Surface Finish | No.1, 2B, BA, No.4, No.8, Mirror (custom available) |
| Tolerance (OD) | ±0.05 mm – ±0.50 mm (per ASTM A213 / ASME SA-213) |
| Tolerance (Wall) | ±10% of nominal wall thickness |
Hardness State & Springback Compensation Data
| Hardness State | Typical Hardness (HV) | Springback Angle | Recommended Overbend | Applications |
|---|---|---|---|---|
| Soft / Annealed (SA) | ≤ 120 HV | 1° – 3° | 1° – 3° overbend | High-formability bends, tight-radius forming, hygienic piping |
| Half-Hard (H) | 120 – 160 HV | 3° – 6° | 3° – 6° overbend | General structural bends, moderate-strength requirements |
| Hard / Full-Hard (HW) | ≥ 160 HV | 5° – 10° | 5° – 10° overbend | High-pressure systems, precision angle-critical assemblies |
Important: The springback values above are representative ranges based on standard tube OD and wall thickness. Actual springback is influenced by tube diameter, wall thickness, bend radius, material grade, and bending method. Wenzhou Jixing Metal Materials Co., Ltd recommends a first-piece trial bending procedure to calibrate the exact springback compensation angle before commencing batch production. This ensures dimensional accuracy within specified tolerances and minimizes scrap and rework costs.
Manufacturing Process
The production of our stainless steel coil tube follows a rigorous, multi-stage manufacturing process designed to ensure consistent material quality, dimensional accuracy, and predictable forming behavior.
- Raw Material Selection: High-purity stainless steel slabs or ingots are sourced from certified mills, with full chemical composition analysis (MOC) and mechanical test certificates provided for every heat.
- Hot Rolling: Slabs are reheated and hot-rolled into hollow tube blanks through a seamless or welded process, depending on the grade and specification requirements.
- Piercing & Elongation: The tube blanks are pierced and progressively elongated through a series of reduction stands to achieve the target OD and wall thickness.
- Heat Treatment & Annealing: Tubes are solution-annealed in a controlled atmosphere furnace to achieve the desired hardness state — soft (SA), half-hard (H), or hard (HW). This step is critical as it directly determines the springback behavior during downstream bending operations.
- Precision Sizing & Straightening: Cold-drawn or cold-rolled sizing ensures tight dimensional tolerances. Straightening operations eliminate residual curvature to achieve a straight, uniform tube.
- Surface Finishing: Tubes are pickled, passivated, and optionally polished to the required surface finish grade. Passivation removes free iron from the surface, restoring the full corrosion resistance of the stainless alloy.
- Coiling: Finished tubes are wound onto precision coil reels at controlled tension to prevent deformation, kinking, or surface damage. Each coil is protected with anti-corrosion wrapping and moisture-absorbing desiccants.
- Quality Inspection: Every coil undergoes dimensional verification (OD, wall thickness, straightness), surface inspection (visual and eddy-current testing), and mechanical property testing (tensile, hardness, impact). Springback calibration data is documented and provided with each shipment.
Applications
Our stainless steel coil tube with springback compensation data serves a wide range of industries where precision bending and forming are essential:
- Heat Exchangers & Boilers: U-bend tubes, hairpin tubes, and serpentine coils for shell-and-tube heat exchangers, condensers, evaporators, and boilers. The predictable springback data ensures accurate U-bend geometry for optimal heat transfer surface area.
- HVAC & Refrigeration: Evaporator and condenser coils, refrigerant piping, and air distribution ductwork. Coil tube eliminates intermediate welds, improving system reliability and reducing leak points.
- Automotive & Transportation: Exhaust systems, fuel lines, brake lines, and structural tubing. Hardness-state selection allows engineers to balance formability with post-form strength requirements.
- Food & Beverage Processing: Sanitary piping systems, brewing equipment, dairy processing lines, and CIP (Clean-in-Place) systems. Electropolished and passivated surfaces meet FDA and 3-A sanitary standards.
- Pharmaceutical & Medical: GMP-compliant process piping, bioreactor components, and medical device tubing. Full traceability and certification documentation are provided.
- Chemical & Petrochemical: Corrosion-resistant process piping, reactor internals, and heat transfer coils for aggressive chemical environments. 316L and duplex 2205 grades are commonly specified.
- Energy & Power Generation: Superheater tubes, economizer coils, and thermal oxidizer components. 321 and 310S grades withstand extreme thermal cycling and oxidation.
- Construction & Architecture: Structural bracing, handrail systems, decorative cladding, and architectural features requiring precision bending to complex profiles.
Quality Certifications & Standards
Wenzhou Jixing Metal Materials Co., Ltd maintains rigorous quality management systems and adheres to internationally recognized standards:
- ISO 9001:2015 — Quality Management System certification ensuring consistent product quality and customer satisfaction.
- ISO 14001:2015 — Environmental Management System certification demonstrating commitment to sustainable manufacturing practices.
- ASTM A213 / ASME SA-213 — Seamless and welded austenitic stainless steel tubing for heat exchangers and similar service.
- ASTM A269 / ASME SA-269 — Seamless and welded austenitic stainless steel tubing for general service.
- ASTM A312 / ASME SA-312 — General requirements for seamless and welded austenitic stainless steel tubing.
- EN 10216-5 — European standard for welded and seamless ferritic, martensitic, and austenitic stainless steel tubes.
- GB/T 12771 — Chinese national standard for stainless steel tubes for fluid transport.
- GB/T 14976 — Chinese national standard for cold-rolled stainless steel tubes for fluid transport.
- API 5L — Available for energy sector applications requiring API compliance.
- CE / PED — Pressure Equipment Directive compliance for EU market applications.
Inspection & Documentation
Each shipment includes comprehensive documentation to support traceability and compliance verification:
- Mill Test Certificate (MTC) / En 10204 3.1 Certificate
- Chemical Composition Analysis (full heat analysis)
- Mechanical Test Report (tensile, hardness, impact)
- Dimensional Inspection Report
- Springback Compensation Data Sheet (calibrated per hardness state and bend geometry)
- Material Traceability Records (heat number, coil number, production date)
- Non-Destructive Testing Report (eddy current, ultrasonic, as applicable)
Unique Selling Points
- Precision Springback Compensation Data: Unlike standard suppliers, Wenzhou Jixing provides documented springback compensation data for each hardness state — soft annealed (1°–3°), half-hard (3°–6°), and hard (5°–10°) — enabling downstream fabricators to set accurate overbend angles and achieve first-time-right dimensional accuracy.
- First-Piece Trial Bending Protocol: We recommend and support a first-piece trial bending procedure before batch production, allowing customers to calibrate exact springback values for their specific tube dimensions, bend radius, and equipment configuration. This eliminates guesswork and minimizes production waste.
- Multi-State Hardness Options: Availability of soft, half-hard, and hard temper states allows engineers to precisely match the material's forming behavior to their application requirements — from tight-radius hygienic bends to high-strength pressure-rated assemblies.
- Seamless & Welded Options: Both seamless and welded coil tube configurations are available, giving customers flexibility in selecting the optimal manufacturing method for their specific service conditions and budget.
- Wide Dimensional Range: From micro-bore tubing (3 mm OD) to large-diameter pipe (168 mm OD), our product range covers virtually every coil tube application in industry.
- Full Traceability & Certification: Every coil is fully traceable from raw material to finished product, with complete documentation supporting regulatory compliance, quality audits, and warranty claims.
- Custom Surface Finishes: From industrial No.1 finish to mirror-polished surfaces, our surface treatment capabilities ensure the tube meets both functional and aesthetic requirements.
Technical Support & Ordering Information
Wenzhou Jixing Metal Materials Co., Ltd provides comprehensive technical support throughout the product selection, ordering, and implementation process. Our engineering team can assist with:
- Grade and hardness state selection based on application requirements
- Springback compensation calculations for specific bend geometries
- Material specification matching to project standards and codes
- Custom coil length and packaging configurations
- Sample provision for trial bending and qualification testing
- Ongoing technical consultation for production optimization
For detailed quotations, technical datasheets, or sample requests, contact Wenzhou Jixing Metal Materials Co., Ltd directly. We are committed to delivering premium stainless steel coil tube solutions that meet the most demanding precision forming requirements in global industry.