Hard Anodizing

Hard Anodizing

Hardcoat Anodize or simply Hard Anodize is a dense anodic coating of aluminum oxide applied by converting a properly cleaned and deoxidized aluminum alloy component into an oxide film using a suitable electrolyte, typically sulfuric acid cooled to nearly freezing, and applied voltages upwards of 100 volts at an applied current density of 24-36 amps per square foot.

Hardcoat Anodize is Type III which is done under more exacting process conditions resulting in a harder, denser, thicker, and more abrasion resistant coating. Hardcoat thicknesses can vary from 0.0005 to 0.0030” and beyond but is dependent on the specific alloy being anodized

We are processing specifications that cover Hardcoat Anodize

MIL-A-8625, Type III

AMS 2469

ASTM B580, Type A

ISO 10074

MIL-A-63576 ( PTFE Sealed )

AMS 2482 ( PTFE Sealed )


Bharat ElectroChem offers cutting-edge hard anodizing services tailored to meet the stringent requirements of various industries. With our expertise and state-of-the-art facilities, we deliver superior quality, precision, and durability in every hard anodizing application.

What is Hard Anodizing?

Hard anodizing, also known as Type III anodizing, is an electrochemical process that produces a thick, dense, and highly wear-resistant oxide layer on the surface of aluminum and its alloys. Unlike traditional anodizing processes, hard anodizing results in a significantly thicker oxide layer, providing exceptional hardness and durability.

The Hard Anodizing Process

PreparationBefore the anodizing process begins, thorough cleaning and surface preparation are essential to remove any contaminants and ensure optimal adhesion of the anodic coating.

AnodizingThe aluminum substrate is immersed in an electrolytic solution and subjected to an electric current. This causes an oxide layer to form on the surface of the aluminum through the process of controlled oxidation. Unlike standard anodizing, hard anodizing involves higher voltages and lower temperatures, resulting in a thicker and denser oxide layer.

SealingAfter anodizing, the aluminum undergoes a sealing process to enhance corrosion resistance and improve surface finish. Various sealing methods, such as hot water sealing or nickel acetate sealing, may be employed depending on the specific requirements of the application.

Benefits of Hard Anodizing

Exceptional HardnessHard anodizing produces a dense oxide layer that significantly increases the surface hardness of aluminum, making it highly resistant to wear, abrasion, and scratching.

Corrosion ResistanceThe thick anodic coating formed during hard anodizing provides superior corrosion resistance, protecting the underlying substrate from environmental factors such as moisture, chemicals, and salt spray.

Enhanced DurabilityComponents subjected to hard anodizing exhibit enhanced durability and longevity, making them ideal for applications that require robust and long-lasting performance.

Applications of Hard Anodizing

AerospaceHard anodizing is commonly used in the aerospace industry to protect critical components such as aircraft fittings, hydraulic systems, and structural elements from wear, corrosion, and fatigue.

AutomotiveAutomotive components subjected to harsh operating conditions, including pistons, cylinder liners, and suspension parts, benefit from the exceptional hardness and corrosion resistance provided by hard anodizing.

Military and DefenseHard anodizing is widely employed in military and defense applications for its ability to enhance the durability and performance of firearms, weapon components, and tactical equipment.

Customized Solutions

At Bharat ElectroChem, we understand that each project has unique requirements. Our experienced team works closely with clients to develop customized hard anodizing solutions tailored to their specific applications, performance criteria, and budget constraints.

Contact Us

Experience the benefits of high-quality hard anodizing services with Bharat ElectroChem. Contact us today to discuss your project requirements and learn how we can assist you in achieving your goals.