Black Oxide Classic

Black oxide is a conversion finish commonly applied to steel parts when a matte black appearance and mild corrosion resistance are wanted. It is often paired with an oil or sealant because the oxide layer alone is not a heavy-duty barrier.

It slows corrosion but does not provide the same protection as a thick coating such as plating or powder coat. Parts exposed to moisture still need oil, wax, or another protective treatment.

Black oxide is a very thin finish, so it generally has little effect on tight dimensions compared with thicker coatings. Critical parts should still be checked against the finisher's process tolerances.

It produces a subdued black or charcoal surface with a matte appearance rather than a glossy painted layer. The final shade can vary with the steel, preparation, and post-treatment.