Product Details
These screws are engineered for strength, aesthetics, and a flawless fit, with features tailored to specific environmental and performance needs.
- DIN 7991 Countersunk Head: The screw features a flat-topped, conical head (typically with a 90-degree angle) that is designed to sit perfectly within a pre-drilled countersunk hole. This allows the head to become flush with the surrounding material, creating a smooth, safe, and visually appealing surface free of any protrusions.
- Internal Hex Socket (Allen) Drive: The head incorporates an internal hexagonal recess, designed for use with a standard hex key (Allen wrench). This drive style allows for high-torque application without the risk of cam-out, ensuring a secure and reliable fastening while protecting the drive from external damage.
- High-Strength Carbon Steel: These screws are forged from quality carbon steel and are available in a variety of property classes to handle different load requirements, including:
- Grade 8.8: A high-tensile steel ideal for most industrial, automotive, and structural applications.
- Grade 10.9 & 12.9: Very high-strength steels for critical, high-stress assemblies that demand maximum clamping force and load-bearing capacity.
- Versatile Black Finish Options:
- Black Oxide: This is a conversion coating that turns the surface of the steel black. It provides mild corrosion resistance (best suited for dry, indoor environments or when oiled), enhances wear resistance, and offers a non-reflective matte finish. It causes minimal dimensional change, making it ideal for precision parts.
- Black Zinc Plating: This finish involves electroplating a layer of zinc onto the steel, followed by a black chromate conversion coat. It provides significantly better corrosion resistance than black oxide, making it suitable for applications in damp or moderately corrosive environments while still providing a sleek black appearance.
Product Parameters
The technical specifications for our DIN 7991 Black Oxide / Black Zinc Hex Socket Countersunk Head Cap Screws are detailed below.
| Parameter | Specification |
|---|
| Product Name | DIN 7991 Flat Head Hex Socket Bolt |
| Standard | DIN 7991 |
| Material | Carbon Steel |
| Property Class / Grade | 4.8, 8.8, 10.9, 12.9 |
| Surface Treatment | Black Oxide, Black Zinc Plated |
| Head Style | Countersunk (CSK) / Flat Head |
| Drive Style | Internal Hex Socket (Allen) |
| Diameter Range | M4 – M24 |
| Brand Name | Duojia |
| Place of Origin | Hebei, China |
| Key Feature | Flush-mount design with aesthetic and protective black finishes |
| Application | Machinery, Electronics, Furniture, Heavy & General Industry |
Product Features
These high-performance screws are engineered to deliver a superior finish and reliable performance:
- Perfect Flush-Mount Finish: The countersunk head design allows the screw to sit perfectly level with the material surface, ensuring a smooth, clean, and snag-free finish.
- Dual Finish Versatility: Choose between Black Oxide for a non-reflective, wear-resistant finish ideal for machinery, or Black Zinc for enhanced corrosion protection in more demanding environments.
- High Tensile Strength: Made from high-grade carbon steel (including 8.8, 10.9, and 12.9), these bolts provide the strength needed for secure, load-bearing joints.
- Sleek Aesthetic: The uniform black finish provides a clean, professional look, making it a popular choice for visible fasteners in electronics, furniture, and automotive interiors.
- Secure High-Torque Installation: The internal hex drive enables controlled, high-torque tightening for a solid and reliable connection without stripping the head.
- DIN Standard Compliance: Manufactured to precise DIN 7991 standards, guaranteeing dimensional accuracy, consistent quality, and interchangeability.
Product Applications
The combination of a flush profile and versatile black finishes makes these screws ideal for a variety of industries:
- Machinery and Tooling: Used for securing panels, guards, and fixtures where a non-protruding head is required and the black oxide finish reduces glare and adds wear resistance.
- Electronics Enclosures: Perfect for assembling cases, racks, and faceplates, providing a clean, professional appearance.
- Automotive: Ideal for interior trim, dashboard assemblies, and other components where a flush, non-reflective fastener is needed.
- Furniture and Cabinetry: Used in high-end furniture and architectural woodworking to create strong, hidden joints with a modern aesthetic.
- General Manufacturing: A versatile fastener for any assembly that requires a strong bolt with a clean, flush-mounted black finish.
