China Suppliers Factory Galvanized Fish-Scale Hollow Wall Expansion Anchors - High Strength Wedge Bolts for Various Applications

Name: Galvanized Fish-Scale Multi-Segment Expansion Anchor
Material: High-quality carbon steel
Standards: GB / DIN / ANSI
Grade: 4.8 / 8.8 (High strength)
Sizes: M6, M8, M10, M12, M14, M16 (Length 60mm - 200mm, customizable in multiple sections)
Surface Treatment: Environmentally friendly blue-white zinc / yellow zinc
Design Features: Equipped with sharp fish-scale double-edged barbs and a multi-segment expansion structure, our anchors feature a top ring-shaped anti-slip knurling and are compatible with various head shapes. They also come with a hot-dip galvanized anti-corrosion protective layer.
Applications: Ideal for reinforcement of hollow brick/perforated brick walls, installation of door and window profiles, curtain walls, heavy-duty railings, outdoor supports, ceiling suspension, pipeline hoisting, and industrial equipment shelving.
Delivery Time: 15-30 days after receiving advance payment
Origin: China
Brand: JGD
Minimum Order Quantity: 10,000 pieces, negotiable
Samples: Available
Packaging: Boxed/Bulk/Pallet or customized packaging
OEM: Available
Suppliers: We are a trusted factory in China, providing high-quality products to meet your needs.

304 Stainless Steel Cross Recessed Countersunk Head Self-Tapping Screws01

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Key Features

Our self-tapping screws are crafted from food-grade 304 stainless steel and treated to achieve metric Grade 12.9 ultra-high strength, overcoming the traditional hardness limitations of standard stainless steel. Featuring a countersunk Phillips head design, these screws can be installed flush with the workpiece surface for a zero-profile finish, making them ideal for precision electronics and architectural decoration. We have optimized the thread geometry for different substrates (metal, wood) to ensure low-torque driving with high-torque clamping, effectively preventing stripping. As a superior alternative to standard Tek screws, these fasteners perform exceptionally well in thin sheet metal connections, providing an intelligent fastening solution that balances aesthetics with high load-bearing capacity.

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Precision Manufacturing Process

From wire rod to finished product, we strictly adhere to multiple international standards including ISO, DIN, ANSI, and GB. Utilizing multi-station cold forging technology, we ensure shank diameter tolerances are controlled within microns. Threads are formed through a precision thread rolling process to enhance fastening force. For non-standard requirements, we employ optical imaging sorters to reject minute defects like head cracks. In post-treatment, we offer a wide range of surface finishing options: from conventional zinc plating and nickel plating to highly corrosion-resistant Hot-Dip Galvanizing (H.D.G.), as well as decorative polishing and black anodizing. We even provide food-grade passivation treatment, ensuring every screw has a prolonged fatigue life in demanding environments.

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Transparency & Customization

As a source factory, we are committed to breaking down the information barriers of traditional trade. From mill certificates for raw materials to hardness grades (covering Grade 4.8 to Grade 12.9, as well as A2-70 and A4-80 marine-grade stainless steel), all test data is traceable. We support full-chain customization: dimensionally, we can adjust thread length and head thickness according to drawings; functionally, we can combine processes like sandblasting, electrophoretic coating (e-coating) , or chrome plating. Whether you need British Standard (BS) fasteners or require a special colored anodized finish, we offer small-batch sampling. This ensures that when you purchase fasteners from us, you not only receive high-quality products but also full transparency and control over the entire process, from material selection to packaging.

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No Pre-Drilling · Rust Resistant · More Secure

This stainless steel Phillips countersunk self-tapping screw, with its rust-resistant and corrosion-resistant material, one-step self-tapping design, and aesthetically pleasing countersunk head structure, has become the preferred solution for metal substrate fastening scenarios that is efficient, reliable, and aesthetically pleasing.

Product Details

Manufacturing Process

✔ Multi Station Cold Heading Technology
✔ Intelligent Heat Treatment System
✔ Micron-Level Thread Rolling Process
✔ Fully Automatic Optical Sorting
✔ Environmentally Friendly Surface Treatment
✔ Metallographic & Mechanical Laboratory

Quality Control

✔ Raw Material Source Locking
✔ Full Batch Traceability
✔ Third Party Material Certification
✔ Transparent Process Parameters
✔ Salt Spray Test Monitoring
✔ International Standard Compliance

Customization

✔ Customizable Head/Slot Shapes
✔ Special Material Applications
✔ Extra Large/Long Specifications
✔ Integrated Component Assembly
✔ Surface Treatment Colors
✔ Personalized Packaging

Technical Service

✔ On-Site Failure Analysis
✔ Selection & BOM Optimization
✔ Installation Tool Guidance
✔ Inventory Management (VMI)
✔ Free Sample Making & Testing
✔ International Standard Interpretation

Sharp Fish-Scale Bidirectional Barbs

Sharp fish-scale barbs spiral along the surface, embedding into hollow brick walls to prevent rotation and slipping. Under rotation or pull-out stress, they anchor firmly, offering several times higher holding power than smooth sleeves – ensuring permanent, non-shifting fixing for curtain walls and heavy railings.

Multi-Segment Staged Expansion

Unique multi-segment staged expansion – each petal opens sequentially during tightening, progressively pressing against the hole wall. The design compensates for hole deviations, ensuring full contact and even force distribution, avoiding stress concentration that could crack hollow bricks – ideal for porous and lightweight blocks.

Dual Corrosion Protection + Anti-Slip Knurling

Carbon steel with blue-white or yellow zinc plating resists moisture and mild corrosion for indoor/outdoor use. Top anti-slip knurling provides friction during tightening, preventing cam-out and ensuring torque accuracy. Fatigue-tested, it resists loosening under vibration, with long replacement cycles in railings and racking.

Factory Environment & Products

High-Quality Stainless Steel Self-Tapping Screw Display

Frequently Asked Questions

Q1: What materials are used for your self-tapping screws?

We primarily use high-grade 304 stainless steel and carbon steel with blue-white or yellow zinc plating for superior corrosion resistance.

Q2: How do the fish-scale barbs improve performance in hollow bricks?

The bidirectional barbs spiral into the material, creating a mechanical lock that prevents the screw from rotating or slipping, significantly increasing pull-out strength.

Q3: Can I request custom head shapes or special sizes?

Yes, we offer flexible customization for head/slot shapes, extra-long specifications, and specific surface treatment colors to meet your project requirements.

Q4: How do you ensure the quality of each batch?

We utilize a full traceability system with furnace number batch locking, micron-level thread rolling, and fully automatic optical sorting to ensure zero-defect delivery.

Q5: Do you provide technical support for installation?

Absolutely. Our technical services include on-site failure analysis, selection calculations, and guidance on choosing the correct installation tools.

Q6: Are your products compliant with international standards?

Yes, all our fasteners undergo rigorous testing in our joint laboratory and come with third-party material certifications complying with international standards.