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Views: 222 Author: Loretta Publish Time: 2025-09-29 Origin: Site
Content Menu
● Key Manufacturers and Suppliers in Japan
>> Hamanaka Chain Manufacturing Co., Ltd.
>> Showa Giken Industrial Co., Ltd.
● Manufacturing Process of Kenter Shackles
● Certifications and Standards
● Applications of Kenter Shackles in Japan's Marine Industry
● Installation and Maintenance Best Practices
● OEM Services and Customization
● FAQ
>> What materials are commonly used in Japanese Kenter shackles?
>> How do I select the correct size and grade of Kenter shackle for my application?
>> Are Japanese Kenter shackles certified by international classification societies?
>> Can Japanese manufacturers provide customized Kenter shackles for OEM clients?
>> What installation and maintenance practices are recommended for Kenter shackles?
Kenter shackles are indispensable components in the marine and offshore industry, serving as critical connectors for anchor chains, mooring systems, and heavy lifting operations. Japan, with its advanced industrial base and strong maritime tradition, is home to several top manufacturers and suppliers of kenter shackles. These companies combine state-of-the-art manufacturing processes, stringent quality controls, and comprehensive OEM services to deliver products that meet international standards and customer-specific needs. This article provides an extensive overview of the top Kenter Shackle Manufacturers and Suppliers in Japan, highlighting their products, manufacturing processes, certifications, and applications in the maritime sector.
A Kenter shackle, sometimes referred to as a connecting shackle or split link, is a specially engineered link used primarily for connecting lengths of anchor chains or attaching anchor chains to anchors and mooring systems. Unlike conventional U-shaped shackles, a Kenter shackle features a robust split design where two halves are joined by a tapered connecting pin. This design ensures high strength, durability, and reliability under demanding marine conditions.
Kenter shackles are forged from high-strength steel alloys and manufactured to withstand the dynamic forces experienced at sea, including tension, shock loads, and corrosion from saltwater exposure. They come in various grades and sizes suitable for different chain diameters and operational roles in anchoring, mooring, and lifting.
Japan's industrial landscape supports several reputable Kenter shackle manufacturers known for precision engineering and adherence to quality standards.
Based in Himeji, Hamanaka Chain Manufacturing is a leading name recognized for its advanced chain and shackle production. Their Kenter shackles are engineered to meet rigorous standards for strength and corrosion resistance, making them suitable for use in shipbuilding, port infrastructure, and offshore platforms. The company combines modern forging techniques with automated heat treatment to ensure consistent product performance.
Nichiboku Ltd. is widely known in Japan for manufacturing an extensive range of marine shackles, including Kenter shackles, hooks, rings, and slings. The company's products comply with Japanese Industrial Standards (JIS) as well as international certifications, offering reliability and safety for industrial lifting, marine construction, and anchoring applications.
Showa Giken Industrial focuses on providing robust anchor chain accessories and mooring hardware, including premium-quality Kenter shackles. Their product development emphasizes high tensile strength steel alloys, corrosion resistance, and fatigue durability, which are critical for the maritime environment.
The production of Kenter shackles in Japan involves several meticulous stages to achieve the required mechanical properties and durability:
- Material Selection: Manufacturers utilize specially formulated steel alloys composed of carbon (C), manganese (Mn), silicon (Si), chromium (Cr), molybdenum (Mo), aluminum (Al), and trace elements like nickel (Ni) and copper (Cu). These alloys provide the strength and corrosion resistance necessary for offshore use.
- Forging and Forming: The steel is heated and forged into the characteristic Kenter shackle shape. Precision forging ensures uniform material properties and stress distribution.
- Heat Treatment: A critical step in the manufacturing process is controlled heat treatment involving quenching at very high temperatures (980–1020°C) followed by tempering at 600–650°C. This treatment develops a tempered sorbite microstructure that delivers superior tensile strength (1000–1050 MPa) with high toughness and controlled yield strength, fulfilling international classification society requirements.
- Machining and Assembly: Post forging and heat treatment, components such as the tapered connecting pins are machined with precision. Assembly involves inserting the pins securely, ensuring tight engagement and eliminating potential movement.
- Surface Treatment: To enhance corrosion resistance, Kenter shackles undergo hot dip galvanization, electric galvanizing, black oxidation, or painting. These coatings are essential for long-term sea water exposure.
- Quality Control: Each batch is subjected to rigorous testing including tensile load testing, fatigue resistance, dimensional inspection, and certification against standards such as CCS, KR, GL, LR, BV, and RS classification society rules.
Japanese Kenter shackle manufacturers align their products with both national and international regulations to guarantee safety and performance in demanding marine environments. Certifications commonly held include:
- Japanese Industrial Standards (JIS) for manufacturing practices and material quality.
- Classification Society Approvals: Compliance with China Classification Society (CCS), Korean Register (KR), Germanischer Lloyd (GL), Lloyd's Register (LR), Bureau Veritas (BV), and Russian Maritime Register (RS).
- International Association of Classification Societies (IACS) member standards, ensuring global acceptance.
These certifications provide operators with confidence that the shackles will perform reliably under operational stresses at sea.
Kenter shackles manufactured in Japan serve diverse roles across marine, offshore, and coastal infrastructure:
- Anchor Chain Connection: Connecting varying lengths of anchor chain or attaching chains to different anchor types on vessels ranging from fishing boats to large cargo ships and tankers.
- Mooring Systems: Used in mooring buoys, floating platforms like oil rigs, and offshore wind turbine foundations for secure anchorage.
- Heavy Lifting and Rigging: Applied in shipyards, ports, and construction projects that require strong and secure linkages in rigging assemblies.
- Marine Civil Engineering: Integral for suspension and linkage roles in bridges, dock installations, and underwater pipeline anchoring.
Proper installation of Kenter shackles ensures their longevity and the safety of marine operations:
- Installation: Use appropriate tools such as wrenches, hammers, and cranes. The locking ring must be carefully opened without damage. Chain links need to be perfectly aligned with the shackle slots before gently tapping the connecting pin to secure the joint. Verify that the pin is fully inserted and flush to prevent loosening.
- Load Testing: Gradually apply load to test the shackle's capacity, watching for any signs of slipping or deformation.
- Maintenance: Frequent inspections should be conducted to identify wear, corrosion, or mechanical deformation. Lubricate moving parts as needed and replace shackles showing fatigue or damage.
Japanese manufacturers often provide detailed manuals and technical support for installation and maintenance to ensure optimal user experience and operational safety.
Many prominent Japanese Kenter shackle manufacturers offer OEM services. This includes tailored product specifications such as:
- Custom sizes and grades.
- Specific surface treatments.
- Packaging and logistics solutions.
Such flexibility appeals to international marine equipment brands, wholesalers, and manufacturers seeking reliable supply partners with high-quality, certified products.
Japanese Kenter shackle manufacturers and suppliers exemplify excellence through a combination of advanced metallurgy, rigorous heat treatment processes, quality manufacturing, and compliance with international standards. Companies such as Hamanaka Chain Manufacturing, Nichiboku Ltd., and Showa Giken Industrial continue to deliver reliable and durable Kenter shackles that support a broad spectrum of marine applications, from anchoring to offshore mooring and heavy rigging. Their dedication to OEM customization, quality assurance, and user guidance solidifies Japan's position as a trusted source for high-performance marine shackles worldwide.
Japanese Kenter shackles are primarily forged from specially formulated high-strength steel alloys, including carbon, manganese, silicon, chromium, molybdenum, and trace elements like nickel and copper. These materials are selected for their tensile strength and corrosion resistance, essential for marine environments. Heat treatment further enhances their mechanical properties.
The shackle size must match the chain diameter and intended load rating. Manufacturers provide specifications aligning shackle grades with chain grades, including proof load and breaking strength values. It is critical to follow these guidelines and consult certification data to ensure compatibility and safety.
Yes, manufacturers in Japan produce Kenter shackles compliant with standards set by CCS, KR, GL, LR, BV, RS, and other classification societies, ensuring acceptance and certification for marine and offshore operations globally.
Absolutely. Japanese manufacturers offer OEM services that include custom dimensions, materials, and surface finishes tailored to client needs. These services facilitate global equipment manufacturers and suppliers in sourcing products that meet strict specifications.
Proper installation involves correct alignment of chains and pins, secure locking, and load testing after assembly. Maintenance includes regular inspection for wear, deformation, and corrosion, alongside lubrication and timely replacement of compromised shackles to maintain safety and functionality.
[1](https://patents.google.com/patent/CN102691014A/en)
[2](https://www.wac-corp.com/what-are-the-installation-requirements-of-a-kenter-shackle-2/)
[3](https://www.wac-corp.com/how-to-install-kenter-shackle/)
[4](https://www.hamanaka-chain.co.jp/en/products/)
[5](https://www.classnk.or.jp/hp/pdf/rules/amendments/e-Amendments/14.12.19/720_typ_e.pdf)
[6](https://www.accio.com/supplier/famous-ship-shackle-factory)
[7](https://jiangsuzhongyun.en.made-in-china.com/product/ZnipRUCrhjcL/China-Stud-Anchor-Chain-Japan.html)
[8](https://kitocrosby.com/crosby/)
