Specifications of DIN 6921 hex flange bolts

DIN 6921 refers to the standard for hexagon flange bolts. These bolts are characterized by a hexagonal head with an integrated flange at the bottom. The flange provides a wider surface area, which helps distribute the load and reduces the risk of the bolt loosening due to vibration. Here are some key features and specifications of DIN 6921 hex flange bolts:

1. Material: Hex flange bolts can be made from various materials, including carbon steel, stainless steel, and alloy steel. The choice of material depends on factors such as the application, environmental conditions, and desired strength.

2. Head Type: The head of a hex flange bolt is hexagonal, allowing for easy tightening and loosening with a wrench or socket. The integrated flange beneath the head provides a built-in washer-like surface, eliminating the need for a separate washer.

3. Flange Diameter: The diameter of the flange is larger than that of the bolt's shank, providing a broader bearing surface. This helps prevent the bolt from embedding into the surface of the material being fastened and improves the overall stability of the joint.

4. Thread Pitch: The thread pitch of DIN 6921 hex flange bolts can vary depending on the specific size and application requirements. Common thread pitches include coarse (standard) and fine threads.

5. Drive Type: Hex flange bolts typically feature a hexagonal drive, which allows for easy installation and removal using a wrench or socket. The size of the drive corresponds to the size of the bolt's head.

6. Grade: Hex flange bolts are often graded based on their strength and material composition. Common grades include 8.8, 10.9, and 12.9 for metric bolts, and Grade 2, Grade 5, and Grade 8 for inch-based bolts. The grade is typically indicated on the bolt head for identification.

7. Finish: Hex flange bolts may be available with various finishes to enhance corrosion resistance and aesthetics. Common finishes include plain (uncoated), zinc-plated, galvanized, and black oxide.

8. Application: Hex flange bolts are used in a wide range of applications where a strong and secure fastening solution is required. They are commonly used in automotive, construction, machinery, and equipment assembly.

When selecting DIN 6921 hex flange bolts for a specific application, it's essential to consider factors such as size, material, grade, and environmental conditions to ensure optimal performance and longevity of the fastening system.