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Black Zinc Oxide CSK Flat Head Hexagonal Bolt Screw - China Factory Suppliers for Carbon Steel & Alloy Steel
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Black Zinc Oxide CSK Flat Head Hexagonal Bolt Screw - China Factory Suppliers for Carbon Steel & Alloy Steel

Discover high-quality fasteners from China with our competitively priced products ranging from US $0.4 to $9.99 per piece. As a leading supplier, we maintain a minimum order quantity of 100 pieces to meet your needs. Our factory boasts a monthly supply capability of 10,000 pieces, ensuring timely delivery for your projects. Each fastener undergoes black oxide surface treatment and is available in various materials including carbon steel, alloy steel, and stainless steel. We adhere to international standards such as DIN, GB, UNC, BSW, and JIS, and our products are certified by ISO9001, ISO14001, ISO45001, and SGS. Choose from an extensive range of grades including 4.8, 8.8, 10.9, 12.9, A2-70, A4-70, and A4-80 to match your specific requirements.

    Structure and Characteristics

    Head design:

    • Flat Head: The top surface of the head is flat and can be aligned with the surface of the workpiece after installation, reducing protrusions and suitable for occasions that require a flat or streamlined appearance.
    • Conical bottom surface: The bottom surface of the head is usually conical and can be embedded into the pre made conical counterbore of the workpiece to provide better fit.

    Hexagonal drive:

    • The hexagonal groove in the center of the head (ISO 4762 standard) can fully fit with the internal hexagonal wrench, transmitting large torque and reducing the risk of slipping.

    Threaded section:

    • The thread types are mostly metric coarse teeth (such as M4, M6) or fine teeth (such as M8 × 1.25), and the length and diameter can be customized according to needs.

    Main application scenarios

    • Mechanical manufacturing: used for the assembly of precision equipment (such as machine tools and molds), in areas that require high loads and limited space.
    • The automotive industry: requires highly reliable connections for engine components, transmissions, chassis, and other components.
    • Electronic products: The structural fixation of compact devices such as laptops and mobile phones.
    • Aerospace: Connection points with high requirements for weight and strength in lightweight design.

    Core advantages

    • High torque transmission: The contact area between the hexagonal hole and the wrench is large, which can withstand greater tightening torque.
    • Space saving: The flat head design does not occupy external space, making it suitable for small or aesthetically pleasing installation environments.
    • Anti loosening performance: When used in conjunction with spring washers or thread glue, it can effectively prevent loosening caused by vibration.
    • Aesthetics: After installation, the surface is flat without exposed bolt heads, suitable for products with high appearance requirements.

    Specifications and standards

    texture of material:

    • Carbon steel (surface galvanized, blackened treatment), stainless steel (such as 304/316, corrosion-resistant), titanium alloy (lightweight and high-strength scenario).

    Size standard:

    • Metric (ISO 4762), American (ANSI/ASME B18.3), with a common diameter range of M2 to M24.

    Surface treatment:

    • Galvanized (rust proof), Dacromet (high-temperature corrosion resistance), electrophoretic (decorative coating), etc.

    Frequently Asked Questions

    What materials are available for these flat head screws?

    They are available in carbon steel (with galvanized or blackened surface treatment), stainless steel (such as 304/316 for corrosion resistance), and titanium alloy for lightweight and high-strength scenarios.

    What are the benefits of the flat head and conical bottom design?

    The flat head aligns perfectly with the workpiece surface to eliminate protrusions, while the conical bottom fits into pre-made counterbores to provide a secure and flush fit.

    Which industries commonly use these hexagonal drive screws?

    They are widely applied in mechanical manufacturing (precision equipment and molds), the automotive industry (engine and chassis components), compact electronic products (laptops and phones), and aerospace applications.

    How do hexagonal drives improve installation torque?

    The internal hexagonal groove (complying with standard systems like ISO 4762) maximizes the contact area with the wrench, allowing high torque transmission and reducing the risk of tool slippage.

    What surface treatments can be applied to prevent rusting?

    Common surface treatments include galvanization for standard rustproofing, Dacromet for high-temperature corrosion resistance, and electrophoretic coatings for decorative and protective purposes.