Product Details
These specialized screws are engineered for maximum durability, strength, and a clean aesthetic.
- DIN 7991 Countersunk Head: The screw features a flat-topped, conical head (typically 90 degrees) designed to fit into a countersunk hole. This allows the head to sit completely flush with or below the surface of the workpiece, creating a smooth, professional finish that prevents interference with moving parts or other components.
- Internal Hex Socket (Allen) Drive: The head is equipped with an internal hexagonal recess, allowing for high-torque installation with a standard hex key (Allen wrench). This secure drive system minimizes the risk of cam-out and protects the drive from external damage, maintaining the screw’s clean appearance.
- High-Strength Carbon Steel: Manufactured from high-quality carbon steel, these bolts are available in various property classes to meet demanding strength requirements:
- Grade 8.8: High-tensile steel suitable for most industrial, automotive, and structural applications.
- Grade 10.9 & 12.9: Very high-strength steels for critical, high-stress assemblies requiring maximum clamping force and load-bearing capacity.
- Advanced Dacromet Coating: The key feature of these bolts is the Dacromet coating. This is a non-electrolytic, water-based coating comprised of zinc and aluminum flakes in a chromate binder. Its benefits are significant:
- Superior Corrosion Resistance: Offers exceptional protection against rust, withstanding hundreds of hours of salt spray testing—far exceeding standard zinc plating.
- No Hydrogen Embrittlement: Because the coating is applied without electrolysis, there is no risk of hydrogen embrittlement, which is a critical concern for high-strength fasteners.
- Heat and Chemical Resistance: Maintains its protective properties at elevated temperatures and is resistant to many industrial solvents and chemicals.
- Thin, Uniform Layer: The coating provides excellent coverage without altering thread dimensions, ensuring a consistent fit.
Product Parameters
The technical specifications for our DIN 7991 Dacromet Coated Hex Socket Countersunk Head Cap Screws are detailed below.
| Parameter | Specification |
|---|
| Product Name | DIN 7991 Dacromet CSK Flat Head Hex Socket Bolt |
| Standard | DIN 7991 |
| Material | High-Strength Carbon Steel |
| Property Class / Grade | 8.8, 10.9, 12.9 |
| Surface Treatment | Dacromet |
| 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 | Superior corrosion and heat resistance with a flush finish |
| Application | Automotive, Marine, Aerospace, Heavy Industry |
Product Features
These high-performance screws are engineered to deliver uncompromising performance in the most challenging conditions:
- Exceptional Corrosion Protection: The Dacromet coating provides a robust barrier against rust and environmental corrosion, making it ideal for outdoor, marine, and industrial use.
- Perfect Flush-Mount Finish: The countersunk head design ensures a smooth, non-protruding surface, enhancing both safety and aesthetics.
- High Tensile Strength: Made from high-grade carbon steel (8.8, 10.9, 12.9), these bolts provide the strength needed for critical, load-bearing joints.
- Eliminates Hydrogen Embrittlement Risk: The non-electrolytic application process makes these screws a safe and reliable choice for high-strength fastening.
- Secure High-Torque Installation: The internal hex drive allows for reliable and controlled tightening to achieve optimal clamping force.
- Excellent Heat and Chemical Resistance: The coating performs reliably in high-temperature environments and is resistant to automotive fluids and industrial chemicals.
Product Applications
The unique combination of a flush-mount design and superior protective coating makes these screws indispensable for a wide range of demanding industries:
- Automotive Industry: Ideal for fastening components in engine bays, brake systems, chassis, and underbody parts where resistance to heat, salt, and fluids is critical.
- Marine Equipment: Used in boat and ship construction for securing hardware and fittings exposed to saltwater and harsh marine environments.
- Aerospace and Defense: Suitable for assembling precision components where strength, reliability, and a flush profile are required.
- Wind and Solar Energy: Used in the assembly of wind turbines and solar panel mountings that are constantly exposed to the elements.
- Construction and Infrastructure: Perfect for architectural metalwork, bridges, and other structures requiring long-term durability and corrosion resistance.
- Heavy Machinery: Provides a secure and lasting fastening solution for agricultural, mining, and manufacturing equipment.
