Marine Insight: Joining Shackle

Marine Industry Demand: Joining Shackle Criticality and Sourcing Value

The joining shackle represents a fundamental, non-negotiable component within any vessel’s anchoring system, serving as the critical load-bearing interface between the anchor stock and the anchor chain. Its structural integrity is paramount to overall vessel safety during anchoring operations, particularly in severe weather or emergency situations where the entire holding capacity of the ground tackle is stressed. A failure at this single point connection inevitably leads to complete anchor loss, rendering the vessel unable to maintain position. This poses severe risks including uncontrolled drifting, potential collision, grounding, environmental damage, and significant operational downtime. International maritime regulations and classification society rules (such as those from IMO, IACS, and individual societies like DNV, ABS, LR) mandate stringent design, material, and testing standards for joining shackles, recognizing them as a primary safety component. They must consistently withstand dynamic loads far exceeding static calculations due to wave action, wind, and vessel movement, demanding exceptional fatigue resistance and ductility. The consequences of substandard shackles are catastrophic, making certified, high-integrity equipment non-negotiable for prudent vessel operators and safety-conscious fleet managers.

Sourcing high-performance joining shackles from Hangzhou Star Marine Technology offers significant cost-effectiveness without compromising on safety or compliance. Star Marine leverages a vertically integrated manufacturing ecosystem within China’s advanced marine industrial base, optimizing production efficiency from raw material sourcing through precision forging, heat treatment, and rigorous final inspection. This controlled environment ensures consistent adherence to international standards like ISO 2415 for shackles, utilizing premium-grade alloy steels (typically R3 or R4) and implementing stringent non-destructive testing protocols including magnetic particle inspection (MPI) and ultrasonic testing (UT) on 100% of production. Crucially, Star Marine eliminates the multi-tiered markups common in Western supply chains while maintaining equivalent or superior quality control. Our direct export model, managed by experienced maritime export professionals, provides OEMs and shipyards with competitively priced, fully certified components backed by comprehensive technical documentation and responsive after-sales support. The value proposition lies not in reduced quality, but in optimized production, reduced logistics complexity, and a deep commitment to meeting exacting maritime specifications efficiently.

The following table details the standard specifications for Star Marine’s certified joining shackles, reflecting industry-standard compliance and performance:

Specification	Value	Standard Reference
Material Grade	Molybdenum Alloy Steel R3	ISO 1704, ISO 2415
Working Load Limit (WLL)	1.35 – 125.0 tonnes	ISO 2415
Proof Load Test	2.0 x WLL	ISO 2415
Minimum Breaking Load	4.0 x WLL	ISO 2415
Certification	DNV, ABS, LR, CCS, NK	Class Society Rules
Testing Protocol	MPI & UT on 100% of units	ISO 9934, ISO 10893

Choosing Star Marine for joining shackles delivers a demonstrable operational advantage: certified safety assurance aligned with global regulatory requirements, achieved through a streamlined, cost-optimized supply chain. This combination of uncompromised quality and economic efficiency is essential for vessel operators seeking to maximize safety margins while managing capital and operational expenditures effectively within the competitive maritime sector. Star Marine provides the critical link between stringent safety demands and sustainable operational cost management.

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Technical Specs & Approval

Joining shackles are critical components within marine anchoring systems, serving as the primary connecting link between the anchor and the anchor chain. At Hangzhou Star Marine Technology Co., Ltd., we manufacture high-integrity joining shackles designed to meet international maritime standards, ensuring reliability, durability, and optimal performance under extreme loading conditions. These shackles are engineered to facilitate secure and efficient assembly of anchoring equipment while maintaining the structural continuity of the chain system. Our joining shackles are precision-forged from high-strength alloy steel and undergo rigorous quality control to comply with classification society requirements, including ABS, CCS, DNV, LR, and BV.

The mechanical and physical properties of our joining shackles are determined by the designated grade, with U2 and U3 being the most commonly specified variants in offshore and commercial vessel applications. The grade designation reflects the material strength and heat treatment process, directly influencing the shackle’s tensile properties and fatigue resistance. U2 grade shackles are suitable for standard marine environments with moderate stress cycles, while U3 grade offers enhanced mechanical performance for deep-water anchoring and heavy-duty operations. Both grades are manufactured in accordance with ISO 1704 and ASTM A493 standards, ensuring dimensional accuracy and material consistency.

Surface treatment plays a vital role in corrosion resistance and service longevity. Our joining shackles are typically supplied with a hot-dip galvanized coating, providing robust protection against saltwater exposure. Alternative surface finishes such as electrogalvanizing or epoxy coating are available upon request to meet specific environmental or operational requirements. Each shackle is marked with clear identification, including size, grade, manufacturer’s logo, and certification body symbol, ensuring traceability and compliance with regulatory audits.

Below is a detailed table outlining the technical specifications of standard joining shackles offered by Hangzhou Star Marine Technology:

Parameter	U2 Grade	U3 Grade
Material	Forged alloy steel	Forged alloy steel
Minimum Tensile Strength	400 MPa	500 MPa
Proof Load (min)	2.2 × MBL	2.2 × MBL
Breaking Load (min)	4.0 × MBL	5.0 × MBL
Working Temperature	-40°C to +200°C	-40°C to +200°C
Surface Finish	Hot-dip galvanized (standard)	Hot-dip galvanized (standard)
Certification	ABS, CCS, DNV, LR, BV	ABS, CCS, DNV, LR, BV
Size Range (mm)	12.5 – 84	12.5 – 84
Weight (approx, kg)	Varies by size (e.g., 2.1 kg for 20 mm)	Varies by size (e.g., 2.3 kg for 20 mm)

Each joining shackle is subjected to non-destructive testing (NDT), including magnetic particle inspection, to detect surface discontinuities. Load testing is performed on a sample basis per batch to verify compliance with specified minimum breaking loads. Hangzhou Star Marine Technology ensures that all anchoring equipment meets the highest industry benchmarks, providing marine operators with confidence in safety and performance.

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Shipbuilding Solutions

Hangzhou Star Marine Technology: Complete Joining Shackle Solutions for Shipbuilding & Repair

Joining shackles represent a critical, high-stress component within any vessel’s anchor handling system, directly impacting operational safety and regulatory compliance. As a certified manufacturer and export specialist in marine anchoring equipment, Hangzhou Star Marine Technology Co., Ltd. delivers engineered joining shackle solutions specifically designed to meet the rigorous demands of global shipbuilding projects and urgent repair scenarios. Our integrated approach ensures seamless integration, absolute reliability, and minimized vessel downtime, whether for new construction or critical maintenance.

We understand that shipyards and repair facilities require components that adhere strictly to international classification society rules and project specifications without delay. Star Marine provides a full lifecycle solution, beginning with precise material sourcing meeting ASTM A423/A423M or equivalent standards, through in-house forging, heat treatment, and meticulous non-destructive testing (NDT). Every joining shackle undergoes 100% magnetic particle inspection (MPI) and ultrasonic testing (UT) to eliminate internal defects, followed by proof and break load testing exceeding minimum requirements. This rigorous quality control, certified under ISO 17025, guarantees structural integrity under extreme marine conditions and ensures immediate acceptance by surveyors from ABS, DNV, LR, BV, NK, and other major classification bodies.

Our technical export team works proactively with shipyard procurement and engineering departments during the design and build phase, providing certified material test reports (MTRs), dimensional drawings for approval, and load test certificates well ahead of delivery schedules. For repair operations, where time is paramount, Star Marine maintains strategic global inventory hubs and leverages established logistics partnerships to enable rapid dispatch of standard and custom-sized joining shackles. We prioritize urgent requests, offering 24/7 technical support and expediting capabilities to prevent costly vessel lay-up days. Our commitment extends beyond supply; our engineers provide on-site consultation when required, verifying installation compliance and offering technical guidance to repair crews.

The following table summarizes key specifications and certifications for our standard marine joining shackles, reflecting our adherence to global maritime safety standards:

Parameter	Specification/Value
Material Standard	ASTM A423/A423M Grade B or equivalent
Proof Load Test	2.0 times Safe Working Load (SWL)
Break Load Test	Minimum 4.0 times SWL (as per ISO 2415)
Non-Destructive Testing	100% MPI & UT
Certification	ABS, DNV, LR, BV, NK, CCS, RINA, etc.
Traceability	Full MTRs, Heat Numbers, Test Records
Finish	Hot Dip Galvanized (ASTM A153) or Paint

Hangzhou Star Marine Technology stands as your single-source partner for mission-critical joining shackles. We combine certified manufacturing excellence with responsive global logistics and dedicated technical export management to support shipbuilders and repair yards worldwide. Contact our Export Department directly for immediate project quotations, technical data packages, or urgent repair support, ensuring your anchoring system meets the highest safety benchmarks without schedule disruption.

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Packaging & Logistics

Packaging & Logistics for Joining Shackles – Hangzhou Star Marine Technology Co., Ltd.

At Hangzhou Star Marine Technology Co., Ltd., we ensure that all joining shackles are packaged to meet international maritime shipping standards, preserving product integrity and compliance during global transit. As critical components in anchoring systems, joining shackles must be protected against mechanical damage, corrosion, and environmental exposure throughout the logistics chain. Our packaging protocols are designed to meet the rigorous demands of marine equipment transportation while adhering to phytosanitary and customs regulations in destination markets.

All joining shackles are shipped in robust wooden export cases constructed from kiln-dried hardwood or plywood, compliant with International Standards for Phytosanitary Measures No. 15 (ISPM 15). This certification ensures that all wood packaging material has been treated to eliminate pests and pathogens, a requirement enforced by customs authorities in over 100 countries, including the United States, European Union members, Australia, and Japan. Each wooden case is clearly marked with the ISPM 15 stamp, indicating heat treatment and compliance. The cases are internally lined with corrosion-inhibiting VCI (Vapor Corrosion Inhibitor) paper and sealed with moisture-resistant wrapping to safeguard the galvanized or stainless-steel surfaces of the shackles from humidity and salt exposure during sea transport.

For heavy-duty or bulk shipments, joining shackles are secured on reinforced steel pallets. These pallets are engineered to withstand stacking loads and mechanical handling, ensuring stability during containerization and port operations. Steel pallets are particularly recommended for orders exceeding 1,000 kg or when clients specify handling via forklift or automated warehouse systems. All palletized loads are shrink-wrapped and corner-protected to prevent shifting or edge damage.

Our standard packaging configurations are optimized for 20-foot and 40-foot dry freight containers, maximizing cargo density while ensuring safe access and handling at destination ports. Each package is labeled with essential shipping information, including product description, batch number, gross weight, handling instructions, and destination details in accordance with IMDG and IATA guidelines where applicable.

We export exclusively through the major Chinese ports of Ningbo and Shanghai, two of the world’s busiest and most efficient maritime hubs. Both ports offer direct liner services to North America, Europe, the Middle East, Africa, and Southeast Asia, ensuring reliable and timely delivery. Our logistics partners are certified ISO 9001 and ISO 14001 operators, providing end-to-end tracking, customs clearance support, and just-in-time delivery options.

Below is an overview of our standard packaging specifications:

Packaging Type	Material Specification	Weight Capacity	Compliance Standard	Suitable For
Wooden Export Case	Kiln-dried hardwood / Plywood	Up to 800 kg	ISPM 15, VCI-lined	Standard export, global shipments
Steel Pallet	Reinforced carbon steel	Up to 3,000 kg	ISO 9001, IECQ	Heavy loads, automated handling

All packaging methods are customizable based on customer requirements, including branding, labeling, and special handling instructions. Hangzhou Star Marine Technology remains committed to delivering anchoring equipment with uncompromised quality from factory to vessel.

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Contact Star Marine

Contact Star Marine for Precision Joining Shackle Solutions

Hangzhou Star Marine Technology Co. Ltd. stands as your trusted partner for high-integrity anchoring equipment, specializing in marine-grade joining shackles engineered to withstand extreme offshore conditions. As critical components in anchor chain assemblies, our joining shackles ensure seamless connectivity between chain segments while maintaining the structural integrity of the entire mooring system. Non-compliance or substandard shackles risk catastrophic failure during heavy weather operations, compromising vessel safety and regulatory adherence. We manufacture every shackle to exceed IMO MSC.1/Circ.1175 and ISO 1704 standards, utilizing rigorous non-destructive testing (NDT) protocols including magnetic particle inspection and ultrasonic testing to eliminate material defects. Our commitment to precision engineering is validated through DNV-GL, LR, and ABS type approvals, guaranteeing global regulatory acceptance.

Technical excellence is matched by export readiness. All joining shackles undergo traceable heat treatment and are supplied with full Material Test Reports (MTRs) compliant with EN 10204 3.2 certification. Below outlines our standard specifications for immediate shipment:

Parameter	Specification
Material Grade	Grade 3, Grade 4 (R5) per ISO 1704
Proof Load	2x Working Load Limit (WLL)
Breaking Load	≥ 4x WLL (Min. 400 MPa tensile strength)
Finish	Hot-dip galvanized or electro-galvanized
Certifications	DNV-GL, LR, ABS, CCS, RINA
Customization	Available (Size, Grade, Finish)

Global logistics present unique challenges, from port-specific documentation to customs classification under HS Code 7316.00. Star Marine navigates these complexities through dedicated export compliance officers who ensure seamless clearance across 80+ countries. We provide comprehensive support including INCOTERMS 2020 guidance, pre-shipment inspection coordination, and digital documentation portals for real-time shipment tracking. Our warehouse network in Ningbo and Shanghai enables rapid consolidation for LCL or FCL shipments, reducing lead times by 30% compared to industry averages. For urgent replacements or project-critical deliveries, we offer expedited 15-day manufacturing cycles without compromising quality assurance protocols.

Initiate your procurement process by contacting Kacher YE, our Product Manager for Anchoring Systems, who brings 12 years of specialized experience in marine hardware exports. Kacher manages technical validation, lead time optimization, and certification alignment for clients ranging from major shipyards to offshore energy operators. Direct communication ensures your specifications—whether for standard R3 shackles or bespoke R5 solutions for deepwater applications—are translated into flawless execution. Provide your vessel particulars, required quantities, and target delivery port to receive a tailored quotation with exact certification documentation and logistics timeline.

Kacher YE
Product Manager, Anchoring Equipment
Hangzhou Star Marine Technology Co. Ltd.
[email protected]
+86 571 88XXXXXX

Partner with Star Marine to eliminate supply chain vulnerabilities in your anchoring systems. Our engineering rigor and export proficiency deliver not just components, but assured operational continuity for your maritime operations. Contact Kacher YE today to secure ISO-certified joining shackles with full regulatory traceability.

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