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Non-Magnetic Fasteners--suitable for precision machinery and aerospace applications, avoiding magnetic interference to the equipment

Special Material Bolts--include super stainless steel, titanium alloys, nickle-based alloys, copper-nickle alloys, cobalt alloys, NASA AMS high-performance materials, etc.

Plastic Fasteners---It is lightweight and corrosion resistance

Classification Society Fasteners---used in ships and marine engineering

High-End Special Raw Material Spring Wire---with high tensile strength

Precision Machined Parts --Ultra High Precision,used in precision electronics, medical equipment, semiconductor equipment, inspection instrument, optical equipment and other fields.

Low Temperature Fasteners-- low Temperature stability, resistance to corrosion

High Temperature Fasteners-- maintain high strength under high temperatures

High Strength Alloy Fasteners--high temperature resistant and Ultra-high strength

High-Strength Stainless Steel Fasteners Inconel Bolts

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China Classification Society Fasteners - Reliable Suppliers & Factory for Marine Engineering Applications

Classification society fasteners are specialized fasteners that are certified by classification societies for applications in marine environments such as ships and marine engineering. Selecting, sourcing, and installing these fasteners must adhere to stringent international maritime safety standards.

Our fasteners are extensively utilized in various sectors including special shipbuilding, offshore oil drilling platforms, submarine pipelines, and offshore wind power. When used in critical components, obtaining a classification society certificate for these fasteners is essential. As a leading supplier in China, our factory is dedicated to providing comprehensive certification options which include:

(Classification society inspection certificate

(Classification society type approval certificate

(Classification society product approval certificate

Product Detail

Products Features

🔩 1. Material Selection

In high-temperature environments (>200℃), 42CrMo chromium-molybdenum alloy steel (such as A193 B7) should be used. It can withstand temperatures up to 480℃ and has a tensile strength of ≥860 MPa.
Extremely cold environments (<-50℃) recommend A320 L7 material with nickel-chromium-molybdenum composite strengthening.

🔒 2. Anti-Loosening Technology

Wedge-shaped lock washers (such as the Nord-Lock system) are used. The geometric structure with a slope angle greater than the thread rise angle is adopted to prevent vibration loosening. Radial fine teeth form indentations on the contact surface.

⚠️ The creep vibration test is used to verify anti-loosening performance and is applicable to scenarios with dynamic loads such as wind turbine towers and ship decks.

Application

Classification Society Fasteners (Certified Shipbuilding Fasteners) are specialized fasteners rigorously certified by international ship classification societies (such as DNV, ABS, LR, etc.). Their application fields mainly focus on ships, marine engineering, and related industries.

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(1) Ship Structure Connection Bolt/nut combinations used for critical parts such as decks, bulkheads, and keels must comply with ISO 3506-3 standards (salt spray corrosion resistance grade ≥ 720 hours).
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(2) Power System Fixed Bolts of the main unit base must pass dynamic load tests (tensile strength ≥ 800 MPa); material is mostly 316L stainless steel.
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(3) Offshore Platform Construction Connection components of the mooring frame must pass the -40℃ low-temperature impact test and comply with the DNV-OS-C501 specification.
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(4) LNG Storage Tank Installation Low-temperature flange bolts should be made of nickel-based alloys (such as Inconel 718) to ensure sealing performance under -196℃ conditions.
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(5) Dock Mooring System Locking nuts must have self-locking function (torque attenuation rate ≤ 5%); material is duplex stainless steel 2205.
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(6) Offshore Wind Turbine Tower Foundation ring bolts must meet ISO 4014 tolerance grade (M24–M64) and have a shear strength of ≥ 600 MPa.
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(7) Tidal Energy Device Underwater fasteners need to undergo bio-adhesion protection treatment (coating thickness ≥ 50 μm).
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(8) Anchor Fixation of Cross-Sea Bridge Prestressed anchor components must undergo 2 million fatigue tests and comply with the EN 1090 standard.

Frequently Asked Questions (FAQ)

❓ What materials are recommended for fasteners used in high-temperature environments above 200℃?

For high-temperature environments exceeding 200℃, 42CrMo chromium-molybdenum alloy steel (such as A193 B7) is recommended. This material can withstand temperatures up to 480℃ and offers a tensile strength of ≥860 MPa, making it suitable for demanding thermal applications.

❓ How does the Nord-Lock wedge-shaped lock washer system prevent loosening?

The Nord-Lock system uses a geometric structure with a slope angle greater than the thread rise angle, which mechanically resists vibration-induced loosening. Additionally, radial fine teeth create indentations on the contact surface, providing a secure clamping effect that is verified through creep vibration tests.

❓ Which classification societies certify shipbuilding fasteners, and what standards must they meet?

Shipbuilding fasteners are certified by internationally recognized classification societies such as DNV, ABS, and LR. Fasteners used in ship structure connections must comply with ISO 3506-3 standards, requiring a salt spray corrosion resistance grade of ≥720 hours to ensure long-term durability in marine environments.

❓ What fastener material is suitable for LNG storage tanks operating at -196℃?

For LNG storage tank installations requiring operation at -196℃, low-temperature flange bolts made from nickel-based alloys such as Inconel 718 are recommended. These materials maintain structural integrity and sealing performance under extreme cryogenic conditions.

❓ What are the key requirements for fasteners used in offshore wind turbine towers?

Foundation ring bolts for offshore wind turbine towers must comply with ISO 4014 tolerance grades for bolt sizes ranging from M24 to M64. They must also achieve a shear strength of ≥600 MPa to withstand the dynamic mechanical loads experienced in offshore wind energy environments.

❓ What protection treatment is required for underwater fasteners in tidal energy devices?

Underwater fasteners used in tidal energy devices must undergo bio-adhesion protection treatment with a minimum coating thickness of ≥50 μm. This treatment prevents marine organism attachment and corrosion, ensuring the long-term reliability and performance of fasteners in submerged environments.