Product Details
These premium screws are defined by their unique head design, superior material, and high-performance drive system.
- DIN 7991 Countersunk Head: The defining characteristic of this screw is its countersunk (CSK) or “flat head” design. The head has a flat top and a conical bearing surface (typically 90 degrees) that fits perfectly into a pre-drilled countersunk hole. This allows the screw head to sit completely flush with the surrounding material, creating a smooth, safe, and aesthetically pleasing surface free of protrusions.
- Internal Hex Socket (Allen) Drive: The head features an internal hexagonal recess, designed for use with a hex key (Allen wrench). This drive style allows for high-torque application without the risk of cam-out, ensuring a secure and reliable fastening. The internal nature of the drive also protects it from external damage.
- Premium Stainless Steel Construction: The core advantage of these screws lies in their material composition, available in grades to suit specific environmental demands:
- A2 Stainless Steel (Type 304): The most popular choice, offering excellent corrosion resistance in freshwater, atmospheric conditions, and food-grade environments. It is ideal for general construction, furniture, and machinery.
- A4 Stainless Steel (Type 316): Known as “marine grade,” A4 contains molybdenum, which provides superior resistance to chlorides (saltwater), acids, and other harsh chemicals. It is essential for marine, coastal, and chemical plant applications.
- Plain Finish: These screws are supplied with the natural, bright finish of stainless steel. They are inherently corrosion-resistant and require no additional plating, ensuring a durable, clean surface that will not chip, flake, or rust.
Product Parameters
The technical specifications for our Stainless Steel DIN 7991 Hex Socket Countersunk Head Cap Screws are detailed below.
| Parameter | Specification |
|---|
| Product Name | Hexagon Socket Countersunk Head Cap Bolt DIN 7991 |
| Standard | DIN 7991 |
| Material | Stainless Steel (SS304/A2, SS316/A4) |
| Property Class / Grade | A2-70, A4-70, A4-80 |
| Surface Treatment | Plain (Bright Finish) |
| 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 installation with superior corrosion resistance |
| Application | Machinery, Furniture, Architectural Hardware, Heavy Industry |
Product Features
These high-performance screws are engineered to deliver a flawless finish and long-lasting reliability:
- Perfect Flush-Mount Finish: The countersunk head design allows the screw to sit perfectly level with the material surface, creating a smooth, clean, and snag-free finish.
- Superior Corrosion Resistance: Manufactured from A2 and A4 “marine grade” stainless steel, providing exceptional protection against rust, moisture, and chemicals for long-term durability.
- High-Strength and Reliable: Available in high-tensile grades like A2-70 and A4-80, ensuring strong and secure clamping force for demanding applications.
- Secure High-Torque Drive: The internal hex socket allows for controlled, high-torque tightening without the risk of stripping the drive, ensuring a solid connection.
- Hygienic and Aesthetic: The smooth, non-porous surface of stainless steel is easy to clean, making it ideal for food-grade and medical applications, while the flush finish offers a high-end, professional look.
- DIN 7991 Standard Compliance: Manufactured to precise international standards, guaranteeing dimensional accuracy, consistent quality, and interchangeability.
Product Applications
The combination of a flush-mount design and superior material properties makes these screws ideal for a wide range of applications:
- Architectural and Woodworking: Perfect for fastening hardware, panels, and trim in high-end furniture, cabinetry, decking, and architectural installations where a clean appearance is critical.
- Machinery and Tooling: Widely used for securing die fixtures, machine guards, and components where a protruding head would cause interference or a safety hazard.
- Electronics: Ideal for mounting panels, faceplates, and components in electronic enclosures and racks to achieve a smooth, professional exterior.
- Marine and Automotive: Used in boat building, vehicle modifications, and motorsports for fastening panels and fittings where a snag-free surface and corrosion resistance are essential.
- General Manufacturing: A versatile fastener for any assembly that benefits from a strong, corrosion-resistant bolt with a flush finish.
