304 Stainless Steel & Carbon Steel Countersunk Window Frame Sleeve Anchor - Heavy Duty Expansion Bolt from China Suppliers Factory

Name: Window Frame Sleeve Anchor / Countersunk Cross Recessed Expansion Bolt
Material: Manufactured using a dual-material composite process, ensuring durability and performance
Standards: Complies with ETAG 001 and GB/T 22795
Grade: Available in Carbon steel Grade 4.8 and 8.8, and Stainless steel Grade A2-70 (304)
Specifications: Offered in sizes M6-M16, with customizable lengths ranging from 50mm to 200mm
Surface Treatment: Carbon steel options include blue-white zinc, environmentally friendly color zinc, and yellow color zinc; Stainless steel features 360° electrolytic polishing or a natural brushed finish
Design Features: Innovative countersunk cross groove for a sleek finish, elongated gap expansion groove for enhanced grip, high-interlocking diamond pattern for anti-slip performance, and exceptional rust prevention through multi-material construction, offering high tensile and shear strength
Applications: Ideal for door and window installations, curtain walls, railing and handrail fixing, building decoration frameworks, air conditioning setups, and solid brick/concrete substrates
Delivery Time: Fast delivery within 15-30 days upon receipt of advance payment
Origin: Manufactured in China by leading suppliers
Brand: JGD
Minimum Order Quantity: 10,000 pieces, with flexibility for negotiations
Samples: Available upon request
Packaging: Available in boxed, bulk, pallet, or customized options
OEM: Custom manufacturing options available

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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 Line

⚙ Metallographic And Mechanical Joint Laboratory

Quality Control System

🛡️ Raw Material Source Locking

🛡️ Furnace Number Batch Full Traceability

🛡️ Third Party Material Certification

🛡️ Process Parameters Open And Transparent

🛡️ Salt Spray Test Real Time Monitoring

🛡️ International Standard Compliance Declaration

Flexible Customization Capability

🎨 Customizable head/slot Shapes

🎨 Extreme Application Of Special Materials

🎨 Breakthroughs In Extra Large/Long Specifications

🎨 Integrated Assembly Of Components

🎨 Customizable Surface Treatment Colors

🎨 Personalized Packaging And Labeling

Technical Service

🛠️ On-Site Failure Analysis

🛠️ Selection Calculation And BOM Optimization

🛠️ Installation Tool Selection Guidance

🛠️ Inventory Management (VMI) Trusteeship

🛠️ Free Sample Making And Testing

🛠️ International Standard Translation And Interpretation

Dual-Material Composite – Corrosion Resistance Inside & Out

Made with a dual-material process: the sleeve is high-strength carbon steel (Grade 4.8/8.8) or 304 stainless steel, while all internal expansion wedges and screws are 304 stainless steel. This design ensures high tensile strength and rigidity from the sleeve, while critical threaded and wedge parts never rust. Even under long-term exposure to window condensation, rain, or humid conditions, internal components remain flexible and reliable – no seizing or failure due to corrosion.

Countersunk Cross Recess + Diamond Knurling – Flush Fit & Anti-Loosening

The countersunk cross recess allows the head to fully embed into the workpiece surface, sitting flush with window frames and curtain wall profiles – aesthetic and never obstructing window operation. Long expansion slots combined with high-grip diamond/anti-slip textures enable 360° uniform expansion tightly against the hole wall, delivering excellent tensile and shear strength. Cross drive works with impact wrenches for easy installation, while diamond textures effectively resist vibration loosening – ideal for outdoor windows and doors subject to wind loads.

Long-Lasting Wear Resistance for Harsh Climates

Internal 304 stainless steel components are electrolytically polished for a smooth, wear-resistant surface; carbon steel sleeves are zinc-plated for overall superior fatigue performance. Proven in cyclic load tests, this anchor withstands decades of window vibration, temperature swings, and weather erosion without failure. The countersunk head is burr-free, protecting sealing gaskets. Compared to ordinary expansion bolts, replacement intervals are greatly extended – providing lifelong reliable anchoring for building curtain walls and premium windows and doors.

Factory Environment

High-Quality Stainless Steel Self-Tapping Screw Display

Frequently Asked Questions

Q1: What makes the dual-material composite anchor superior for window installation?

The dual-material design combines a high-strength carbon steel sleeve for structural rigidity with 304 stainless steel internal components. This ensures the anchor can handle high wind loads while remaining completely rust-proof internally, preventing failure even in humid or rainy environments.

Q2: How does diamond knurling help with vibration?

Diamond knurling creates high-grip textures on the anchor surface. This provides 360° uniform expansion against the hole wall, significantly increasing friction and resistance to vibration loosening caused by wind or mechanical operation.

Q3: Are these anchors suitable for high-end curtain wall projects?

Yes. With features like flush-fit countersunk heads, electrolytic polishing, and zinc plating, our anchors meet international standards for fatigue performance and aesthetics, making them ideal for premium curtain walls and architectural windows.

Q4: Can I request custom sizes or head shapes?

Absolutely. Our flexible customization capability allows for tailored head/slot shapes, extra-long specifications, and personalized surface treatment colors to meet specific architectural requirements.

Q5: How do you ensure the quality and traceability of the materials?

We utilize a full traceability system based on furnace numbers and batches. Every order includes third-party material certifications and is monitored through our metallographic and mechanical joint laboratory.

Q6: What technical support do you offer for large-scale projects?

We provide comprehensive services including on-site failure analysis, selection calculation, BOM optimization, and guidance on installation tool selection to ensure perfect project execution.