An Introduction to DIN 7991

DIN 7991 is a international standard for socket head cap screws. These screws are widely used in various industries such as automotive, aerospace, and construction. They are known for their flat socket heads, which allow for a flush installation and a high-strength fastening solution.

Size Specifications

DIN 7991 screws come in various sizes to suit different applications. The size of DIN 7991 screws is determined by the diameter and length of the screw shaft. The most common sizes range from M2 to M20.

The diameter of DIN 7991 screws is measured in millimeters (mm). For example, an M4 screw has a diameter of 4 mm. The length of the screw is also measured in millimeters and can range from 6 mm to 100 mm or more, depending on the specific requirement.

The size of the socket head is standardized based on the diameter of the screw. The socket size for an M4 screw would typically be 3 mm, while an M12 screw would have a socket size of 8 mm.

Common Uses

  DIN 7991 socket head cap screws are used in a wide range of applications. Some common uses include:

1. Industrial Machinery: These screws are commonly used in machinery manufacturing due to their high-strength and reliability.
2. Automotive Industry: DIN 7991 screws are used in the assembly of engines, transmissions, and other critical components in the automotive sector.
3. Electronics: These screws find application in the assembly of electronic devices and equipment.
4. Structural Engineering: DIN 7991 screws are used in construction projects for fastening structural components together securely.

Summary：

In conclusion, DIN 7991 socket head cap screws are a widely used standard in various industries. With their standardized size specifications, these screws provide a reliable and efficient fastening solution. Whether it's in industrial machinery, automotive assembly, electronics, or construction, DIN 7991 screws offer high-strength fastening and a flush installation. Understanding the sizes and common uses of these screws is essential for choosing the right fastening solution for your specific application.