Product Details
These screws are meticulously engineered for superior strength, a flawless fit, and decades of reliable service in harsh conditions.
- DIN 7991 Countersunk Head: The screw features a flat-topped, conical head (typically 90 degrees) that is designed to sit perfectly within a pre-drilled countersunk hole. This allows the head to become completely flush with the material surface, creating a smooth, safe, and professional finish that prevents snagging and interference.
- 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, which is especially important for coated fasteners.
- High-Strength Material Options: To meet diverse structural and load-bearing requirements, these bolts are available in a range of materials:
- Carbon Steel & Alloy Steel: Available in high-tensile property classes including 8.8, 10.9, and 12.9 for demanding structural applications.
- Stainless Steel: Offered in A2-70 and A4-70 grades for applications requiring inherent corrosion resistance in addition to strength.
- Superior Hot-Dip Galvanized (HDG) Coating: The defining feature of these bolts is their Hot-Dip Galvanized finish. This process involves immersing the fastener in a bath of molten zinc, creating a thick, durable, and metallurgically bonded coating.
- Exceptional Corrosion Resistance: The thick zinc layer provides a robust barrier against rust and corrosion, far surpassing standard zinc plating. It is the industry standard for long-term outdoor and marine exposure.
- Sacrificial Protection: The zinc coating sacrificially corrodes to protect the underlying steel, even if the surface is scratched or abraded.
- Abrasion Resistance: The alloy layers formed during the galvanizing process create a tough finish that is highly resistant to mechanical damage.
Product Parameters
The technical specifications for our Handan HDG DIN 7991 Hex Socket Countersunk Head Cap Screws are detailed below.
| Parameter | Specification |
|---|
| Product Name | Handan HDG DIN7991 CSK Hex Socket Bolts |
| Standard | DIN 7991 |
| Material | Carbon Steel, Alloy Steel, Stainless Steel |
| Property Class / Grade | 4.8, 8.8, 10.9, 12.9; Stainless Steel A2-70, A4-70 |
| Surface Treatment | Hot Dip Galvanized (HDG) |
| Head Style | Countersunk (CSK) / Flat Head |
| Drive Style | Internal Hex Socket (Allen) |
| Diameter Range | M3 – M36 |
| Brand Name | Duojia |
| Place of Origin | Handan, Hebei, China |
| Key Feature | Maximum corrosion resistance for outdoor use with a flush finish |
| Application | Construction, Marine, Infrastructure, Heavy Industry |
Product Features
These heavy-duty screws are engineered to deliver uncompromising performance in the toughest environments:
- Maximum Corrosion Protection: The thick Hot-Dip Galvanized coating provides decades of reliable protection against rust, making it ideal for outdoor, coastal, and industrial settings.
- Perfect Flush-Mount Finish: The DIN 7991 countersunk head ensures a smooth, non-protruding surface, enhancing safety and aesthetics in structural and architectural applications.
- High Tensile Strength: Available in high-strength grades (8.8, 10.9, 12.9), these bolts provide the clamping force and shear strength required for critical, load-bearing connections.
- Heavy-Duty Durability: The metallurgically bonded HDG coating is tough and abrasion-resistant, ensuring the fastener’s integrity during transport, handling, and installation.
- Secure High-Torque Installation: The internal hex drive allows for controlled and reliable tightening, ensuring optimal clamping force without damaging the protective coating.
- Sourced from a Fastener Hub: Manufactured in Handan, a global center for fastener production, ensuring quality, expertise, and competitive factory-direct supply.
Product Applications
The combination of a flush profile and extreme corrosion resistance makes these screws the premier choice for long-lasting structural applications:
- Construction and Infrastructure: Ideal for steel structures, bridges, guardrails, and building facades where long-term durability is essential.
- Marine and Coastal Environments: Used in the construction of docks, piers, boat lifts, and on marine vessels exposed to saltwater spray.
- Automotive and Transportation: Perfect for chassis assembly, trailer frames, and heavy-duty vehicle attachments that face road salt and extreme weather.
- Industrial and Agricultural Equipment: Provides a secure and lasting fastening solution for heavy machinery, processing plants, and farm equipment exposed to the elements.
- Outdoor Structures: The best choice for assembling playgrounds, stadiums, communication towers, and architectural metalwork.
