Hard-Condition (H) Fully Cold-Worked Stainless Steel Coil Tube
Manufactured by Wenzhou Jixing Metal Materials Co., Ltd, this fully cold-worked hard-condition stainless steel coil tube is engineered to deliver superior pressure resistance and mechanical integrity for demanding industrial applications. As part of the company's extensive product specification range, this coil tube represents the highest hardness state available, optimized for applications where maximum structural strength is paramount.
Product Overview
The Hard (H) condition coil tube is produced through extensive cold working processes that significantly enhance the mechanical properties of the base stainless steel material. This fully cold-worked condition achieves a Vickers hardness of HV ≥ 280, positioning it as the most pressure-resistant grade within the coil tube product family. The material is supplied in coil form, providing flexibility in downstream fabrication while maintaining consistent mechanical performance throughout the entire length.
This product is specifically designed for applications where maximum yield strength and pressure containment are critical, making it an ideal choice for high-pressure fluid and gas handling systems, pressure vessels, and specialized process piping components.
Material & Properties
Mechanical State Classification
This coil tube falls under the Mechanical State product specification category, specifically in the Hard (H) sub-classification. The material undergoes complete cold working without intermediate annealing, resulting in maximum work hardening and the highest achievable hardness within the coil tube product line.
Key Mechanical Properties
- Hardness: HV ≥ 280 (Vickers Hardness), representing the maximum hardness achievable in the coil tube product range
- Elongation: ≥ 10%, providing adequate ductility for forming into prefabricated elbows and straight pipe sections
- Pressure Resistance: Maximum within the product family, suitable for high-pressure applications
- Work Hardening: Fully cold-worked condition ensures consistent and predictable mechanical performance
Material Characteristics
- Excellent resistance to internal pressure and mechanical loading
- Enhanced wear resistance due to elevated hardness
- Consistent dimensional accuracy maintained through cold working
- Smooth surface finish achieved through precision cold forming processes
Specifications
| Parameter | Specification | Standard / Method |
|---|---|---|
| Product Name | Coil Tube (Hard Condition) | — |
| Product Category | Product Specifications / Mechanical State | — |
| Sub-Classification | Hard (H) — Fully Cold Worked | — |
| Hardness | HV ≥ 280 | Vickers Hardness Test |
| Elongation | ≥ 10% | Tensile Test |
| Pressure Rating | Maximum within coil tube range | Hydrostatic Test |
| Form | Coil (continuous length) | — |
| Intended Use | Prefabricated elbows or straight sections only | — |
| Supplier | Wenzhou Jixing Metal Materials Co., Ltd | — |
Manufacturing Process
Cold Working Procedure
The hard-condition coil tube is produced through a rigorous multi-stage cold working process that progressively deforms the stainless steel material to achieve the target mechanical properties:
- Material Preparation: High-quality stainless steel raw material is selected and inspected to ensure base composition meets specification requirements.
- Initial Forming: The material is shaped into tube form using precision cold drawing or cold rolling equipment.
- Progressive Cold Reduction: Multiple passes of cold working are applied without intermediate annealing, progressively increasing dislocation density and achieving maximum work hardening.
- Coiling: The fully cold-worked tube is wound onto coils using controlled tension systems to prevent surface damage or deformation.
- Quality Inspection: Each coil undergoes hardness testing (HV), tensile testing (elongation), dimensional verification, and surface quality inspection.
Process Advantages
- Elimination of annealing cycles ensures maximum achievable hardness
- Consistent mechanical properties maintained throughout the entire coil length
- Precision dimensional control through calibrated cold forming equipment
- Improved surface finish and dimensional accuracy compared to hot-formed alternatives
Applications
Primary Applications
- High-Pressure Piping Systems: Ideal for applications requiring maximum pressure resistance in fluid and gas handling
- Prefabricated Elbows: The ≥10% elongation allows controlled forming into elbows for piping assemblies
- Straight Pipe Sections: Suitable for direct use as pressure-containing straight segments in process systems
- Pressure Vessel Components: Used in high-pressure containment applications where structural integrity is critical
Industry Sectors
- Petrochemical and oil & gas processing
- Power generation and high-pressure steam systems
- Chemical processing with elevated pressure requirements
- Hydraulic and pneumatic systems
- Specialized industrial equipment manufacturing
Application Limitations
Important: Due to the fully cold-worked hard condition, this coil tube is limited to prefabricated elbows or straight sections only. The material's reduced formability (compared to annealed or semi-hard conditions) restricts its use in applications requiring complex bending or multi-directional forming. Users should select appropriate mechanical state grades for applications demanding extensive forming operations.
Quality Certifications
Testing & Inspection Protocol
- Hardness Verification: Vickers hardness testing performed at multiple points along each coil to confirm HV ≥ 280 compliance
- Tensile Testing: Elongation verified to be ≥ 10% through standardized tensile testing procedures
- Hydrostatic Pressure Testing: Each coil subjected to pressure testing to confirm maximum pressure resistance capability
- Dimensional Inspection: Outer diameter, wall thickness, and coil dimensions verified against specification tolerances
- Surface Quality Assessment: Visual and dimensional inspection for surface defects, scratches, or deformation
- Material Traceability: Full heat number traceability maintained from raw material through final product
Compliance Standards
- Product specifications aligned with international stainless steel tube standards
- Mechanical properties verified per applicable ASTM/EN testing methodologies
- Manufacturing processes conform to quality management system requirements
- Material certification documentation provided with each shipment
Unique Selling Points
- Maximum Pressure Resistance: The HV ≥ 280 hardness represents the highest pressure containment capability within the Wenzhou Jixing coil tube product family
- Superior Structural Integrity: Fully cold-worked condition provides exceptional resistance to deformation under load
- Predictable Performance: Consistent mechanical properties throughout the coil ensure reliable engineering calculations
- Comprehensive Quality Assurance: Multi-stage testing protocol ensures every coil meets stringent performance criteria
- Flexible Delivery Format: Coil form enables efficient downstream processing and reduced material waste
- Specialized Application Focus: Optimized specifically for high-pressure prefabricated components where maximum strength is required
Technical Advisory
When selecting the Hard (H) condition coil tube, engineers should account for the material's reduced formability compared to softer mechanical states. This grade is best suited for applications where the tube will be used as straight sections or formed into simple elbows with controlled radii. For applications requiring complex forming, multi-radius bends, or deep drawing operations, consideration should be given to semi-hard (1/2H) or annealed (A) condition alternatives available within the same product family.
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive product range across all mechanical states, enabling customers to select the optimal grade for their specific application requirements while ensuring consistent quality and reliable supply.