U1 U2 U3 Stud Link Anchor Chain Marine Grade Corrosion Resistant Welded Heat Treated Anchor Chain

Product Description:

Material Advantages:

Adopt high-quality marine special alloy steel round bar, main grades include CM490 (U2 grade) 
The steel forging process optimizes the internal metal structure, eliminating internal stress and significantly improving the chain's tensile, impact and fatigue resistance

Stud Link Type
With internal reinforcing studs, the link structure is stable and not easy to deform, suitable for heavy load anchoring of large ships and offshore engineering
Nominal diameter range: 12.5mm - 120mm; standard link size: inside length 4D, outside width 3.6D (D = nominal diameter)
Standard section length 27.5m, customizable for non-standard lengths according to customer needs
Studless Link Type (Open Link)
No internal studs, lighter weight, easy to match with large shackles, avoiding stud loosening faults
Nominal diameter range: 12.5mm - 70mm; ideal for medium and small vessels, offshore permanent mooring and auxiliary anchoring
Proof load and breaking load meet U2/U3 grade international standards, with accurate load-bearing parameters

Manufacturing Process:

1. Raw Material Preparation and Pretreatment
Select suitable low-carbon steel wire rod (e.g., Q235) with a diameter slightly larger than 8mm to allow for subsequent processing.

Surface treat the steel wire rod to remove oxide scale, oil, and other impurities to avoid affecting subsequent forming and welding quality.

Draw the steel wire rod to a standard diameter of 8mm using a wire drawing machine to ensure the dimensional accuracy of the chain material.

2. Chain Forming and Welding

Chain Braiding: Using specialized chain braiding equipment, bend the 8mm steel wire into "日" (sun) shaped chain links, controlling the inner width and length of the links according to DIN766 standards.

Welding: Use flash butt welding or resistance welding to weld the joints of each chain link to form a closed chain link. After welding, remove weld slag to ensure a smooth joint.

Shaping: Use shaping equipment to correct the shape and size of the chain links, ensuring smooth connection between adjacent links without deformation or jamming.

3. Heat Treatment and Strength Testing

Heat Treatment: The welded chain undergoes overall tempering treatment (e.g., annealing, quenching + tempering) to eliminate welding stress and improve the chain's tensile strength and toughness, meeting the load requirements of marine applications.

Tensile Testing: Randomly selected finished chains are subjected to tensile tests to verify whether their tensile strength and breaking load meet DIN766 standards. Unqualified products are rejected.

Appearance and Dimensional Inspection: The surface flatness and link dimensional deviations of each chain are inspected to ensure there are no defects such as cracks or dents.

4. Hot-Dip Galvanizing for Corrosion Protection

Pre-treatment: The chain surface is cleaned again to remove oil and rust, followed by pickling to remove rust. Finally, it is immersed in a flux to improve the adhesion of the zinc layer.

Hot-Dip Galvanizing: The chain is immersed in molten zinc at 440-460℃ to form a uniform and dense zinc alloy coating on the chain surface. The thickness must meet corrosion protection requirements (typically ≥85μm). Post-treatment: Remove the galvanized chain, cool it, and remove excess zinc nodules from the surface. If necessary, perform passivation treatment to further enhance corrosion resistance.

5. Finished Product Inspection and Packaging: Conduct a final inspection of the galvanized chain, including zinc layer adhesion (e.g., cross-cut test), appearance (no uncoated areas, peeling), and dimensional verification.

Inspected and qualified chains are wound and packaged to the specified length (e.g., 10 meters/coil), labeled with specifications, standards, production date, and other information, and prepared for shipment.

Technical drawings:

Features:

- Corrosion Resistant Surface Treatment: Optional hot dip galvanized or black bitumen coating, effectively resisting seawater corrosion, rust, and wear, extending the service life of the chain even in tropical or aggressive seawater environments. Custom color coating is available according to customer requirements.
- Comprehensive Specifications: Diameter ranges from 12.5mm to 130mm, covering all common marine anchor chain sizes. Standard length is 27.5m per shot (with an odd number of links), and bespoke lengths and assemblies can be manufactured to meet specific customer requirements. The safety factor is 4:1, with proof load and breaking load strictly compliant with industry standards (see detailed specification table below).

- Certified & Reliable: Manufactured in accordance with IACS UR W29, UR W18, and IMORULES standards, with SGS certification available. Each chain is inspected before delivery to ensure quality meets international marine safety requirements.

Applications:

Widely used in various marine vessels, including cargo ships, passenger ships, offshore platforms, fishing boats, and yachts. Suitable for temporary mooring in harbors, sheltered areas, and permanent mooring in deep waters, as well as offshore oil and gas development mooring systems. It is the core component of ship anchoring equipment, ensuring vessel stability in different sea conditions.

Certification & Load Performance
Obtained authoritative certifications from major international marine classification societies: CCS, ABS, BV, DNV-GL, LR, NK, KR, RINA, IRS
U2 grade proof load 41.2KN-1280KN, breaking load 82.6KN-2560KN; U3 grade proof load 56.4KN-1810KN, breaking load 112.8KN-3620KN (matching with different nominal diameters)
Standard weight 85.41kg-1032kg per 27.5m, with accurate weight parameters for easy shipping and installation calculation

After-sales:

Customization & After-sales
Support non-standard customization of diameter, length, grade and surface treatment
Provide free product samples (freight collect), and sample delivery with 12-hour quick response to inquiries
Flexible delivery cycle, 15-30 days for regular orders, customizable production plan for bulk orders; FOB Qingdao port optional, supporting T/T, L/C at sight and other payment terms
 
Any question please let us know ,our JinCheng maritime will provide you the best service with 7*24 hours ~