Stainless Steel Coil Tube — Per-Meter Pricing Specification
Supplier: Wenzhou Jixing Metal Materials Co., Ltd.
Product Code: JX-ST-186
Category: Commercial Procurement — Length-Based Pricing (Per-Meter Unit Price)
1. Product Overview
The Stainless Steel Coil Tube (Coil Tube) is a continuous-length stainless steel pipe supplied in coiled form, designed for flexible downstream processing including cutting, bending, forming, and welding. Wenzhou Jixing Metal Materials Co., Ltd. offers this product under a per-meter pricing model (元/米, CNY per meter), which includes the allocation of cutting loss (trimming allowance). This pricing structure is specifically optimized for small-batch orders and custom-length retail orders where individual pieces are cut to specified dimensions from the parent coil stock.
Unlike bulk or length-based pricing that favors large-volume, fixed-length procurement, the per-meter unit price provides maximum flexibility for end-users who require precise, variable lengths without the financial burden of purchasing full coils or standard-length bars. The cutting loss — typically ranging from 3 mm to 10 mm per cut depending on the cutting method and tube outer diameter — is fully absorbed into the per-meter unit price, ensuring transparent and predictable costing.
2. Material & Properties
Stainless steel coil tubes are manufactured from austenitic and ferritic stainless steel grades, selected based on application requirements for corrosion resistance, mechanical strength, and formability. The following table summarizes the typical material grades and their key properties:
| Parameter | 304 (0Cr18Ni9) | 316L (022Cr17Ni12Mo2) | 321 (06Cr18Ni11Ti) | 430 (1Cr17) |
|---|---|---|---|---|
| Composition (Ni %) | 8.0 – 10.5 | 10.0 – 14.0 | 9.0 – 12.0 | — |
| Composition (Cr %) | 18.0 – 20.0 | 16.0 – 18.0 | 17.0 – 19.0 | 16.0 – 18.0 |
| Tensile Strength (MPa) | ≥ 520 | ≥ 480 | ≥ 515 | ≥ 450 |
| Yield Strength (MPa) | ≥ 205 | ≥ 170 | ≥ 205 | ≥ 205 |
| Elongation (%) | ≥ 40 | ≥ 40 | ≥ 40 | ≥ 25 |
| Corrosion Resistance | Good | Excellent (chloride-resistant) | Good (intergranular-resistant) | Moderate (atmospheric) |
| Maximum Service Temperature (°C) | 870 | 870 | 900 | 800 |
| Formability | Excellent | Excellent | Excellent | Good |
Surface Finish Options
- BA (Bright Annealed): Mirror-like, oxide-free surface suitable for food-grade and pharmaceutical applications.
- No. 4 Brushed: Matte finish with uniform grain, commonly used in architectural and decorative applications.
- 2B (Cold-Rolled): Standard industrial finish with moderate surface roughness (Ra ≤ 0.8 μm).
- Polished (Mirror): High-gloss finish (Ra ≤ 0.05 μm) for high-end decorative and optical uses.
3. Specifications
| Specification Parameter | Range / Value | Notes |
|---|---|---|
| Outer Diameter (OD) | Φ3.0 mm – Φ63.0 mm | Custom sizes available upon request |
| Wall Thickness (WT) | 0.3 mm – 3.0 mm | Tolerance: ±10% (GB/T 14976) or ±0.03 mm (precision) |
| Coil Length | 50 m – 300 m per coil | Dependent on OD, WT, and grade |
| Cut Length (Per-Meter Pricing) | 100 mm – 10,000 mm | Custom cut-to-length; cutting loss included in unit price |
| Length Tolerance | ±1.0 mm (standard); ±0.5 mm (precision) | Applies to each individual cut piece |
| Cutting Loss Allowance | 3 mm – 10 mm per cut | Absorbed into per-meter unit price (元/米) |
| Coil Inner Diameter (ID) | Φ63 mm / Φ102 mm | Standard coil core sizes |
| Applicable Standards | GB/T 14976, GB/T 12771, ASTM A554, ASTM A269, EN 10217 | Multi-standard compliance |
| Minimum Order Quantity (MOQ) | 1 meter (per size/grade combination) | Designed for small-batch and retail orders |
Pricing Model Detail
Per-Meter Unit Price (元/米): The unit price is calculated based on the tube's outer diameter, wall thickness, and material grade, and explicitly includes the proportional cost of cutting loss (trim allowance). This eliminates the need for separate trimming charges and simplifies budgeting for end-users.
Applicable Scenarios: Small-batch orders, prototype fabrication, custom-length retail orders, and on-demand cutting services where purchasing full coils or standard-length bars would result in material waste and unnecessary capital tie-up.
4. Manufacturing Process
The production of stainless steel coil tubes at Wenzhou Jixing Metal Materials Co., Ltd. follows a rigorous, multi-stage manufacturing process to ensure dimensional accuracy, surface integrity, and metallurgical quality:
- Strip Preparation: Cold-rolled stainless steel strip is received from certified mills, inspected for thickness, width, and surface defects, and coiled for feeding into the tube mill.
- Coil Forming (Tube Milling): The strip is fed through a series of progressive forming rolls that gradually bend and shape it into a circular cross-section. Precision roll calibration ensures consistent OD and wall thickness throughout the coil length.
- Welding: The formed strip is joined longitudinally using either TIG (Tungsten Inert Gas) welding or automatic laser welding. TIG welding provides a high-quality, oxide-controlled weld seam with excellent mechanical properties. A protective gas (argon or argon-helium mixture) shields the weld zone from atmospheric contamination.
- Heat Treatment (Annealing): The welded coil tube undergoes solution annealing at 1010°C – 1150°C followed by rapid quenching (water or air). This process dissolves carbides, restores full austenitic microstructure, relieves residual stresses, and maximizes corrosion resistance and formability.
- Pickling and Passivation: Post-annealing oxide scale is removed via acid pickling (nitric-hydrofluoric acid blend or environmentally compliant citric acid). Subsequent passivation forms a protective chromium oxide layer (Cr₂O₃) on the surface, enhancing long-term corrosion resistance.
- Sizing and Straightening: The annealed coil tube passes through a sizing unit (plug rolling or cold expansion) to achieve final dimensional accuracy within specified tolerances. Straightening ensures the tube exits the coil in a flat, stable configuration.
- Surface Finishing: Depending on the specified finish, the tube undergoes mechanical polishing, chemical polishing, or electropolishing to achieve the required surface roughness and appearance.
- Cutting and Trimming: For per-meter pricing orders, the coil is cut to the customer's specified length using precision plasma, laser, or shearing equipment. Cutting loss is calculated and included in the per-meter unit price.
- Quality Inspection: Every batch undergoes dimensional measurement (OD, WT, length), hydrostatic pressure testing, surface inspection, and spectrographic composition analysis before dispatch.
- Packaging: Tubes are bundled, wrapped in protective film or paper, and packed in wooden or steel crates for safe transit. Coil products are shrink-wrapped and secured on pallets.
5. Applications
Stainless steel coil tubes supplied under the per-meter pricing model serve a wide range of industrial, commercial, and consumer applications where flexibility in ordering and precision in length are critical:
- Automotive Industry: Exhaust system components, fuel lines, turbocharger piping, and hydraulic lines. Small-batch production runs and custom lengths make per-meter pricing ideal for prototype and low-volume manufacturing.
- Food Processing & Beverage: Conveying pipes for dairy, brewing, and pharmaceutical liquid transfer. BA and polished finishes meet hygienic standards (3-A, EHEDG compliant).
- Medical Devices: Surgical instrument tubing, endoscope sheaths, and dialysis equipment components requiring high purity and precision dimensions.
- Construction & Architecture: Decorative railings, handrails, structural frames, and facade elements. Custom lengths eliminate on-site cutting waste.
- Oil & Gas / Petrochemical: Instrument tubing, sensor housings, and low-pressure process piping in corrosive environments (316L grade).
- Electronics & Heat Exchangers: Refrigerant tubing, condenser tubes, and thermal management components requiring tight dimensional tolerances.
- Consumer Goods: Bicycle frames, furniture legs, appliance components, and sports equipment where custom lengths and surface finishes are essential.
- R&D and Prototyping: Laboratory testing, product development, and pilot runs where small quantities of precise-length tubing are required.
6. Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework supported by the following certifications and compliance standards:
| Certification / Standard | Description |
|---|---|
| ISO 9001:2015 | Quality Management System — Ensures consistent product quality and continuous improvement across all production stages. |
| ISO 14001:2015 | Environmental Management System — Governs environmentally responsible manufacturing practices, waste management, and emissions control. |
| ISO 45001:2018 | Occupational Health and Safety Management — Ensures safe working conditions and risk mitigation for all personnel. |
| CE Marking | Compliance with European Union health, safety, and environmental protection standards for market access. |
| EN 10204 3.1 | Material Test Certificate — Provides third-party verified chemical composition and mechanical property data for each batch. |
| GB/T 14976 / GB/T 12771 | Chinese national standards for seamless and welded stainless steel tubes — Ensures compliance with domestic regulatory requirements. |
| ASTM A554 / A269 | American standards for austenitic stainless steel tubing — Meets international procurement specifications. |
| Nadcap (where applicable) | National Aerospace Quality Assurance — For aerospace-grade heat treatment and welding processes. |
7. Unique Selling Points
- Transparent Per-Meter Pricing: The unit price (元/米) fully incorporates cutting loss allocation, eliminating hidden charges and enabling accurate cost forecasting for small-batch and custom-length orders.
- Zero-Minimum Flexibility: Orders as small as a single meter are accepted, making this offering uniquely suited for prototyping, repair, and low-volume production scenarios.
- Precision Cut-to-Length: Advanced cutting technology ensures length tolerance of ±0.5 mm to ±1.0 mm, reducing downstream processing requirements and material waste.
- Multi-Grade, Multi-Finish Portfolio: Comprehensive range of stainless steel grades (304, 316L, 321, 430, and more) and surface finishes (2B, BA, No. 4, Mirror) available under a single, streamlined ordering system.
- Multi-Standard Compliance: Products conform to GB, ASTM, and EN standards simultaneously, facilitating both domestic and international supply chain integration.
- Full Traceability: Each batch is accompanied by an EN 10204 3.1 material test certificate with full chemical and mechanical property documentation, ensuring complete supply chain traceability.
8. Ordering Guidance
When placing an order under the per-meter pricing model, customers should specify the following parameters to ensure accurate quotation and delivery:
- Material Grade: e.g., 304, 316L, 321, 430, or custom specification.
- Outer Diameter (OD): In millimeters, to one decimal place.
- Wall Thickness (WT): In millimeters, to two decimal places.
- Required Length: Per piece, in millimeters. Multiple lengths in one order are acceptable.
- Quantity: Number of pieces per length specification.
- Surface Finish: 2B, BA, No. 4 Brushed, or Mirror Polished.
- End Condition: Open ends, deburred, chamfered, or threaded.
- Applicable Standard: GB, ASTM, or EN, as required by the end application.