Carbon Steel Blackened Flange Bolts Overview

Carbon steel blackened flange bolts are mechanical connecting components. The main material of them is carbon steel, which is an iron-carbon alloy with a carbon content ranging from 0.0218% to 2.11%. These bolts adopt the blackening treatment process. The blackening treatment, also known as bluing treatment, is a method of metal surface treatment. It mainly forms a black oxide film on the surface of the bolts through chemical oxidation. The main component of this oxide film is ferroferric oxide (Fe₃O₄), and its thickness is generally about 1 – 3μm.

The flange is a special structural part on the bolt. The flange part is usually a flat, disc-shaped structure with bolt holes, used to cooperate with other flanges or connecting parts and achieve connection and fastening by tightening the nuts.

Application of Black Carbon Steel Flange Bolt

• Industrial Pipeline Systems: They are widely used in pipeline connections in industries such as petroleum and chemical engineering. For example, in the pipeline system for transporting crude oil, carbon steel blackened flange bolts are used to connect pipeline flanges. The bolts after blackening treatment have a certain degree of corrosion resistance and good fastening performance, which can ensure the tightness of pipeline connections.
• Mechanical Manufacturing Field: During the assembly process of some large mechanical equipment, such as machine tools and construction machinery, carbon steel blackened flange bolts may be used for the connections between components. They can withstand certain tensile and shearing forces, ensuring the stability of the machine tools during the working process. Moreover, the bolts after blackening treatment have a relatively good appearance.
• Automobile Manufacturing Industry: They are also used in the connections of components in parts such as the automobile chassis. Carbon steel blackened flange bolts can provide reliable connections, prevent the loosening of chassis components, and the blackening treatment can improve the wear resistance of the bolts, prolong their service life, and play an important role in the complex usage environment of automobiles.

Feature of Black Carbon Steel Flange Bolt

Carbon steel blackened flange bolts are made of carbon steel and treated by blackening. The flange structure is convenient for connection. Their characteristics are as follows:

• Mechanical properties: They have relatively high strength. The tensile strength is generally 370 – 630MPa. They can withstand various external forces and have good toughness, being able to resist impact and vibration.
• Surface characteristics: The blackening film enhances the corrosion resistance, can prevent rust in general environments, and has a relatively good black appearance.
• Processing and cost: They have good processing performance, can be cold headed and cut, have low costs, and are applicable to various fields such as industrial pipelines, mechanical manufacturing, and automobile manufacturing where cost sensitivity and certain performance requirements exist.