Stainless Steel Coil Tube Bending Mold Set — CNC & Manual Bending Tooling System
Wenzhou Jixing Metal Materials Co., Ltd presents a precision-engineered bending mold set designed specifically for stainless steel coil tube forming operations. This specialized tooling system is compatible with both CNC bending machines and manual bending equipment, delivering consistent, high-quality bends across a wide range of tube diameters while eliminating common defects such as wrinkling, collapsing, and surface scratching.
Product Overview
The Coil Tube Bending Mold Set is a critical accessory in stainless steel tubing fabrication, engineered to interface seamlessly with industrial bending machines. Each mold assembly is precision-matched to the outer diameter (OD) of the coil tube being processed, ensuring optimal contact geometry and uniform force distribution during the bending cycle. The tooling is categorized under the Installation & Maintenance segment, specifically within the Bending Processing and Bending Tools subcategories, reflecting its essential role in the secondary processing of stainless steel coil tube products.
Unlike generic bending fixtures, this mold set is designed with tube-specific clearance tolerances that directly address the two most prevalent failure modes in stainless steel tube bending:
- Excessive mold clearance — which leads to tube wall wrinkling and ovality distortion
- Insufficient mold clearance — which causes surface scratches, scoring, and material galling
By maintaining the precise dimensional relationship between the bending die, wiper die, and clamp die, this system ensures defect-free bends that preserve both the structural integrity and surface finish of the stainless steel coil tube.
Material & Properties
The bending mold set is manufactured from high-grade tool steels and alloy materials selected for exceptional wear resistance, dimensional stability, and surface hardness under repeated bending cycles:
- Bending Die (Forming Die): Hardened alloy steel (Cr12MoV or equivalent) with surface hardness of HRC 58–62, providing extended service life against abrasive wear from stainless steel tube surfaces
- Wiper Die: Precision-ground tool steel with controlled surface finish (Ra ≤ 0.4 μm) to minimize friction-induced surface damage on the tube outer wall
- Clamp Die: Forged alloy steel with through-hardening treatment, ensuring sufficient grip strength without marring the tube surface
- Optional Surface Treatments: Nitriding, PVD coating (TiN or DLC), or chrome plating available for enhanced corrosion resistance and reduced coefficient of friction in high-volume production environments
Specifications
| Parameter | Specification / Range |
|---|---|
| Compatible Tube OD | 6 mm – 108 mm (custom sizes available upon request) |
| Compatible Tube Wall Thickness | 0.5 mm – 6.0 mm |
| Minimum Bend Radius | 1D – 3D (depending on tube diameter and material grade) |
| Mold Clearance Tolerance | ±0.05 mm (critical dimensional control) |
| Surface Finish (Contact Surfaces) | Ra ≤ 0.4 μm (ground and polished) |
| Hardness | HRC 58–62 |
| Material | Cr12MoV / D2 Tool Steel / Custom Alloy |
| Compatible Equipment | CNC Bending Machines / Manual Bending Tools |
| Applicable Tube Grades | 304, 304L, 316, 316L, 321, 310S, 2205 Duplex, and other austenitic/ferritic/duplex stainless steels |
| Mold Set Composition | Bending Die + Wiper Die + Clamp Die (assembled per tube OD) |
| Wear Life | ≥ 50,000 bending cycles (standard conditions) |
| Customization | Available — non-standard OD, special radius profiles, and proprietary geometries |
Manufacturing Process
Each mold set undergoes a rigorous multi-stage manufacturing and quality assurance process to ensure dimensional accuracy and functional reliability:
- Raw Material Selection: Premium-grade alloy tool steel billets are sourced from certified mills with full chemical composition traceability and mechanical property verification.
- Forging & Pre-Heat Treatment: Billets are forged to near-net shape and subjected to stress-relief annealing to eliminate internal residual stresses and improve machinability.
- Precision Machining: CNC milling, turning, and grinding operations produce the mold cavity geometry with tolerance control within ±0.02 mm on critical bending surfaces.
- Heat Treatment: Through-hardening and tempering cycles achieve the target hardness of HRC 58–62 with controlled distortion limits of ≤ 0.1 mm per 100 mm.
- Post-Grinding & Surface Finishing: Precision grinding and polishing bring all contact surfaces to Ra ≤ 0.4 μm, ensuring smooth tube passage without surface marring.
- Optional Surface Coating: PVD nitride or DLC coatings are applied where enhanced wear resistance or reduced friction is required for high-cycle production.
- Dimensional Inspection & Functional Testing: Each completed mold set is verified using CMM (Coordinate Measuring Machine) inspection and subjected to trial bending runs with representative stainless steel coil tubes to confirm zero-wrinkle, zero-scratch performance.
Applications
This bending mold set is designed for use across a broad spectrum of industries where stainless steel coil tubes are formed into complex geometries:
- Heat Exchanger & HVAC Manufacturing: Production of U-tubes, hairpin bends, and serpentine coil configurations for condensers, evaporators, and radiators.
- Automotive Industry: Bending of exhaust system tubing, fuel lines, brake lines, and turbocharger piping from stainless steel coil stock.
- Oil & Gas / Petrochemical: Fabrication of instrumentation tubing, control valves, and process piping requiring corrosion-resistant bends.
- Food & Pharmaceutical Processing: Forming of hygienic-grade tubing assemblies for CIP/SIP-compatible process lines where surface integrity is paramount.
- Medical Equipment: Precision bending of stainless steel tubing for surgical instruments, infusion devices, and diagnostic equipment housings.
- Construction & Architectural: Production of decorative railings, handrails, and structural framing elements from stainless steel coil tube.
- Aerospace & Defense: Bending of high-grade (310S, 2205) tubing for hydraulic systems, exhaust manifolds, and structural components.
Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management framework to ensure every mold set meets international standards:
- ISO 9001:2015 — Quality Management System certification covering design, manufacturing, and delivery processes
- ISO 14001:2015 — Environmental Management System for sustainable manufacturing practices
- EN 10204 Type 3.1 — Material test certificates provided for all tool steel components
- GD&T Compliance: All critical dimensions verified per ASME Y14.5 geometric dimensioning and tolerancing standards
- Hardness Verification: Each lot undergoes Rockwell hardness testing with documented results
- Traceability: Full batch traceability from raw material mill certificates through final inspection reports
Unique Selling Points
- Defect-Free Bending Guarantee: Precision-engineered mold clearance eliminates wrinkling (from oversized gaps) and scratching (from undersized gaps) — the two most costly defects in stainless steel tube bending operations.
- Dual Compatibility: One mold set design philosophy compatible with both CNC automated bending systems and manual bending tools, maximizing capital utilization and production flexibility.
- Wide Diameter Coverage: Comprehensive mold library spanning 6 mm to 108 mm OD, with custom fabrication available for non-standard sizes, providing a one-source solution for diverse production needs.
- Extended Tool Life: Hardened Cr12MoV construction with optional PVD coatings delivers ≥ 50,000-cycle wear life, significantly reducing tool changeover frequency and production downtime.
- Surface Integrity Preservation: Ra ≤ 0.4 μm contact surfaces protect the critical finish quality of stainless steel coil tubes, ensuring downstream processes (welding, coating, passivation) proceed without surface contamination.
- Engineering Support: Dedicated technical team provides application-specific mold design consultation, including bend radius optimization, springback compensation, and multi-radius sequential bending solutions.