Electro-Polish Co

Hard Coat Anodizing

Hardcoat anodizing produces a much thicker coating of aluminum oxide, penetrating holes and fissures in the surface to create a more uniform appearance than regular anodized aluminum. Aluminum sheets processed by hardcoat anodizing may have a dark brown, gray or black surface, but other colors can be created.

The benefits of hard anodized aluminum instead of using stainless steel are lower overall cost and weight. Machining hard anodized aluminum is easier than penetrating a similar block of stainless steel. Hard coat anodizing also yields a product resistant to harsh weather, salt sprays and abrasive machining processes. Aluminum processed by hard anodizing can be only a few points away from the hardness of diamonds.

Hard anodizing shares many characteristics with sulfuric anodizing, but the two processes have clearly different results. Hard anodizing creates a much thicker aluminum oxide surface with a stronger bond to the original aluminum layer. When shopping for new aluminum cookware, it may pay to look for the descriptions ‘anodized aluminum’ or ‘hard anodized.’ The cookware marked ‘hard anodized’ may prove to be more durable, though possibly a little more expensive.