Surface finishes

Black oxide services

Black oxide is a surface finishing process that resists abrasion, scratches and other types of damage, making it suitable for a wide range of industrial and commercial applications.

Get instant quote

What is Black Oxide?

Black oxide is a conversion coating formed by a chemical reaction between the metal surface and the oxygen in the air. The reaction produces a thin layer of oxide that is black in color. Black oxide is commonly used to protect ferrous metals from corrosion and oxidation. It can also be used to improve the appearance of the metal surface and to increase its resistance to wear and abrasion.

Black oxide coatings can be applied to steel, cast iron, magnesium, copper, and brass. The thickness of the black oxide coating depends on the type of metal and the method of application. Black oxide coatings can be applied with chemicals, heat, or electricity.

Black oxide is not a protective coating in itself, but it can be used in conjunction with other coatings, such as paint or oil, to improve the overall protection of the metal surface.

key properties

Surface preparation	Colors	Applicable materials	Cosmetic availability	Thickness**	Visual appearance
As machined (Ra 3.2μm / Ra 126μin)	Steel, Stainless Steel, Copper	Steel, Stainless Steel, Copper	No	0-30μm / 0-1181μin	Smooth black matte

Black oxide finish

Black metal material is coated by a process in which steel is soaked in alkaline solutions by which iron is converted into magnetite. This compound provides black coating color on polished part. Metals that can undergo the black coating process are copper, zinc, steels, and silver etc. there are 3 various temperatures in this process. The hot temperature and mild temperatures are 141°C and 90 – 120°C. This finally gives a magnetite layer on metal. If the temperature is lower, the cold temperature black coating, this leaves copper selenium coat (Cu₂Se) deposit on the satin finish. After this, the finish step is carried out and metal is coated with oils, waxes, and lacquer. Without this step, the black metal material is highly susceptible to corrosion. Therefore, this step is essential for anti-corrosion properties.

Design considerations for Black oxide

Black oxide provides some level of corrosion resistance, but it is not as effective as other coatings like zinc or chrome. It may not be suitable for applications where the parts are exposed to harsh environments.
Black oxide is not as hard as other coatings and may wear off over time. It may not be suitable for parts that are subjected to high levels of wear and tear.
Black oxide does not adhere well to some types of metals, such as aluminum. It may require additional surface preparation to ensure good adhesion.

The Anpllocnc black oxide process

Black oxide is a conversion coating, compatible with steel, stainless steel and copper, that provides a black appearance and mildly improves corrosion of parts.

Here’s how to apply black oxide:

First run parts through cnc machining and deburring.
Clean parts using alkaline solutions.
Rinse in water.
Black oxidizing. Immerse the part in the hot (135-145ºC) alkaline bath for a period of 5 to 40 minutes depending on the size of the part
Rinse in water.
After-finish treatment. Seal the oxide surface with oil, lacquer or wax. This imparts the desired aesthetic appearance and improves the corrosion resistance of the component.

Black oxide coating Application

Black oxide coating products have dimensional accuracy machined components; therefore, this finish has many applications. Corrosion resistance, good reflective properties and cost effectiveness further add the benefits of using this finish at large scale.

Applications	Description
Medical field	Extremely suitable for medical equipment that is light sensitive like x-rays. Because black coating on steel has high light-absorbing properties.
Electrical components	Timer gears, wire stripper and cutter with black oxide finish provides good electrical properties.
Auto component	Black oxide finish parts like suspension bushing, spark plug, brake valve parts and oil filter can provide good corrosion resistance properties and long lifespan.
Military applications	Black oxide coating materials have used as military equipment like shotgun magazine or military humvees turret. Mid temperature black coatings are mostly utilized for this purpose.
Assembly Tools	High dimensional accuracy of machining components like bearing, fastener, and gauge are common example of black coating assembly tools.

Get Started With Our Black Oxide Coating Services

Unlock the potential of advanced finishing with our premier black oxide services. Whether you prioritize aesthetics, durability, or both, our tailored solutions cater to diverse requirements. Dive deep into a world of refined finishes and let your CNC components stand out with unparalleled quality. Reach out today, and our team will guide you through the transformational journey of black oxide finishing, ensuring impeccable results.