Black Oxide Metal Bolt Grade 12.9 Carbon Steel Bolt M6 M8 Rust Resistance

Grade 12.9 screws are ultra-high-strength fasteners made from SCM435 alloy steel, featuring a minimum tensile strength of 1220Mpa and hardness of 39-44HRC. These bolts are primarily used in textile, hydraulic, injection molding, and mechanical industries.

The black oxide treatment forms a protective oxide film on the metal surface, providing rust prevention while eliminating reflections. This treatment is particularly suitable when strict appearance requirements aren't necessary.

Flange bolts combine a hexagonal head with an integrated flange, offering a larger support area than standard bolts. This design enables higher preload capacity and superior anti-loosening performance, making them ideal for automotive engines and heavy machinery applications.

• Flange design provides superior locking capability compared to standard bolts
• Thinner flange section allows slight deformation for more secure fastening
• Integrated flange eliminates the need for separate washers in many applications
• Critical for wheel hub safety, ensuring stable connection between wheels and vehicle
• Available in various configurations to match different vehicle requirements