Stainless Steel Coil Tube (Coiltube) — Ready Stock Program
Product Overview
The Stainless Steel Coil Tube (Coiltube) offered by Wenzhou Jixing Metal Materials Co., Ltd. represents a strategically maintained inventory of pre-manufactured austenitic stainless steel tubing, coiled for compact storage and rapid deployment. This ready-stock program is specifically designed to address the critical supply chain challenges faced by end-users requiring immediate material availability for emergency repairs, prototype fabrication, and sample trial manufacturing. By maintaining perpetual stock of the most frequently ordered specifications in standard grades 304 and 316L, the program ensures delivery lead times of 1 to 3 business days, significantly outperforming the typical 4–8 week lead times associated with made-to-order coil tube production.
The coil tube format provides several inherent advantages over straight-length tubing: reduced storage footprint, enhanced material utilization during downstream processing (due to minimal cutting waste), and compatibility with automated forming, bending, and welding equipment. The ready-stock initiative positions Wenzhou Jixing Metal Materials Co., Ltd. as a responsive and reliable supplier within the industrial stainless steel supply chain.
Material & Properties
The ready-stock inventory comprises two primary austenitic stainless steel grades, each selected for its balance of mechanical performance, corrosion resistance, and widespread industrial acceptance:
Grade 304 (UNS S30400 / AISI 304)
- Composition: 18–20% Chromium (Cr), 8–10.5% Nickel (Ni), with residual Carbon (C) ≤ 0.08%
- Corrosion Resistance: Excellent resistance to atmospheric corrosion, dilute acids, and organic compounds; suitable for non-chloride environments
- Mechanical Properties: Yield strength ≥ 205 MPa; tensile strength ≥ 515 MPa; elongation ≥ 40%
- Weldability: Superior weldability without preheating; suitable for all common welding processes (TIG, MIG, resistance welding)
- Formability: Excellent cold-forming characteristics; ideal for deep drawing, bending, and cold reduction
- Temperature Range: Continuous service from cryogenic temperatures up to 870°C (oxidation resistance)
Grade 316L (UNS S31603 / AISI 316L)
- Composition: 16–18% Cr, 10–14% Ni, 2–3% Molybdenum (Mo), with residual Carbon ≤ 0.03%
- Corrosion Resistance: Superior resistance to pitting and crevice corrosion, particularly in chloride-containing environments; enhanced resistance to sulfuric acid and marine atmospheres
- Mechanical Properties: Yield strength ≥ 170 MPa; tensile strength ≥ 485 MPa; elongation ≥ 40%
- Weldability: The low-carbon ("L") designation minimizes intergranular corrosion (IGC) risk during welding; excellent weld integrity
- Formability: Good cold-forming characteristics; slightly lower ductility than 304 but compensated by superior corrosion performance
- Temperature Range: Suitable for cryogenic to 870°C continuous service
Specifications
| Parameter | Specification / Range | Standard Reference |
|---|---|---|
| Material Grades | 304 (AISI/UNS S30400), 316L (AISI/UNS S31603) | ASTM A554, ASTM A213, EN 10217-7 |
| Outer Diameter (OD) | 3 mm – 219 mm (common stock sizes: 6.35, 9.53, 12.7, 19.05, 25.4, 31.75, 38.1, 48.3, 60.3, 76.1 mm) | ASTM B534, EN 10217 |
| Wall Thickness | 0.5 mm – 6.0 mm (common stock: 0.8, 1.0, 1.5, 2.0, 3.0 mm) | ASTM A554 |
| Surface Finish | No. 1 (annealed & pickled), 2B (cold-rolled & bright annealed), BA (Bright Annealed) | ASTM A403 |
| Coil Length (per coil) | 50 m – 500 m (typical: 100–300 m) | Manufacturer specification |
| Coil Weight | 200 kg – 2,000 kg (per coil) | Manufacturer specification |
| Manufacturing Method | Seamless (seamless tube) or Welded (ERW — Electric Resistance Welding) | ASTM A213 / ASTM A554 |
| Tolerance — OD | ±0.05 mm (precision grade) to ±0.2 mm (commercial grade) | ASTM B534 |
| Tolerance — Wall Thickness | ±10% (commercial) to ±10% (precision per ASTM A554) | ASTM A554 |
| Delivery Lead Time | 1–3 business days (from confirmed order to dispatch) | — |
| Minimum Order Quantity (MOQ) | 1 coil or partial coil (as per stock availability) | — |
Manufacturing Process
The coil tubes in the ready-stock inventory are produced through rigorous, multi-stage manufacturing processes that ensure dimensional accuracy, metallurgical integrity, and surface quality:
- Slab Casting: Stainless steel ingots are produced via the Basic Oxygen Furnace (BOF) or Electric Arc Furnace (EAF) process, followed by continuous casting into slabs or billets.
- Hot Rolling: Cast slabs are reheated to 1,100–1,200°C and hot-rolled into thin strip or pipe blanks, establishing initial dimensions and grain structure.
- Pickling and Annealing: Hot-rolled material undergoes acid pickling (typically a mix of hydrofluoric acid and nitric acid) to remove scale, followed by controlled annealing to restore ductility and achieve a uniform microstructure.
- Cold Drawing / Cold Reduction: For seamless tube production, hot-rolled pipe blanks are cold-drawn through precision dies to achieve final OD and wall thickness tolerances. This process imparts beneficial strain-hardening and improved surface finish.
- Forming and Welding (for welded tube): For ERW (Electric Resistance Welded) coil tube, cold-rolled strip is formed into a tube shape and the seam is welded using high-frequency electrical resistance. The weld zone is subsequently heat-treated to match the base metal properties.
- Final Annealing: Cold-worked tube is annealed in a protective atmosphere (typically argon or nitrogen) to relieve residual stresses, achieve a fully austenitic microstructure, and ensure optimal mechanical properties.
- Surface Treatment: Final surface finish is achieved through mechanical polishing, chemical brightening, or passivation treatment, depending on the specified finish grade.
- Coiling: Finished tube is coiled onto precision-machined spools with controlled tension to prevent deformation, kinking, or surface damage during storage and transport.
- Quality Inspection: Each coil undergoes dimensional measurement, visual surface inspection, and (where applicable) ultrasonic testing (UT), eddy current testing (ECT), or hydrostatic testing to verify internal and external quality.
Applications
The ready-stock stainless steel coil tube program serves a broad spectrum of industrial applications, with particular emphasis on scenarios where rapid material availability is critical:
Emergency Repair & Maintenance
- Replacement of corroded or damaged piping in chemical processing plants, refineries, and pharmaceutical facilities
- Urgent repair of heat exchanger tubes, condensers, and evaporators in HVAC and power generation systems
- Field replacement of sanitary tubing in food processing and beverage production lines
Prototype & Sample Fabrication
- Rapid prototyping of custom piping systems, heat exchangers, and fluid handling equipment for R&D purposes
- Manufacturing of trial runs for new product development in automotive, aerospace, and medical device industries
- Construction of laboratory-scale reactors, condensers, and analytical instrumentation components
Industrial Applications
- Food & Beverage Industry: Sanitary process piping, milk processing lines, brewing equipment, and food-grade conveying systems (particularly 316L)
- Pharmaceutical Industry: Clean steam lines, purified water (PW) and water-for-injection (WFI) systems, CIP (Clean-in-Place) circuits
- Chemical Processing: Reactor internals, heat exchanger tubes, corrosive fluid transfer lines
- Automotive Industry: Exhaust system components, fuel lines, and structural tubing for lightweight design
- Medical Devices: Endoscope tubing, surgical instrument shafts, and implant-grade component fabrication
- Architecture & Construction: Decorative handrails, structural elements, and architectural cladding
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system and adheres to internationally recognized standards to ensure the reliability and traceability of all products supplied under the ready-stock program:
- ISO 9001:2015 — Quality Management Systems certification, demonstrating commitment to consistent quality and continuous improvement
- ISO 14001:2015 — Environmental Management Systems certification, ensuring environmentally responsible manufacturing practices
- EN 10204 3.1 — Third-party material test certificates provided with each shipment, confirming compliance with specified standards
- Mill Test Reports (MTR): Full chemical composition analysis and mechanical property verification supplied with every coil
- Traceability: Each coil is marked with heat number, grade, dimensions, and manufacturing date for full supply chain traceability
- Material Standards Compliance: ASTM A554, ASTM A213, ASTM B534, EN 10217-7, GB/T 14976 (as applicable)
Unique Selling Points
Unmatched Availability: With conventional 304 and 316L specifications maintained in perpetual ready-stock, customers benefit from 1–3 business day delivery — eliminating the weeks-long lead times that can halt production lines, delay project milestones, or compromise maintenance schedules.
- Reduced Supply Chain Risk: The ready-stock model insulates customers from raw material price volatility, mill production delays, and logistics disruptions that characterize the global stainless steel market.
- Cost Efficiency: Bulk procurement and strategic inventory management allow Wenzhou Jixing Metal Materials Co., Ltd. to offer competitive pricing on frequently ordered specifications, reducing the total cost of ownership for repeat purchasers.
- Flexible Order Quantities: Partial-coil and single-coil orders are accommodated, enabling small-scale projects, prototyping, and emergency repairs without minimum order barriers.
- End-to-End Service: From specification consultation and grade selection to custom cutting, surface treatment, and logistics, the ready-stock program provides a turnkey solution for time-critical material requirements.
- Quality Assurance: Every coil in the ready-stock inventory has passed full incoming inspection, dimensional verification, and (where required) non-destructive testing prior to being designated as available stock.
Supply Chain & Delivery Management
The ready-stock program is integrated into Wenzhou Jixing Metal Materials Co., Ltd.'s broader supply chain management framework, which encompasses:
- Real-time Inventory Tracking: Digital inventory management systems provide customers with up-to-the-minute stock availability information for all grades, sizes, and specifications.
- Expedited Dispatch Protocol: Orders placed by 12:00 PM local time are processed and dispatched within the same business day, with standard transit arrangements for regional and national delivery.
- Logistics Coordination: Professional packaging (wooden pallets, moisture-proof wrapping, protective end caps) and freight forwarding services ensure coil integrity during transit.
- Stock Replenishment Cycle: Inventory levels are continuously monitored and replenished through strategic purchasing from certified mill partners, ensuring uninterrupted availability of standard specifications.
The ready-stock coil tube program from Wenzhou Jixing Metal Materials Co., Ltd. exemplifies a customer-centric approach to stainless steel supply, bridging the gap between manufacturing lead times and end-user urgency. By maintaining a curated inventory of the most in-demand 304 and 316L specifications, the program delivers the dual advantages of premium material quality and exceptional delivery responsiveness — making it an indispensable resource for emergency maintenance, rapid prototyping, and time-sensitive industrial projects.