Matte Black Finish, High-Adhesion Surface, Cost-Effective
We supply Custom Neodymium Magnets finished with a specialized Black Zinc plating.
As shown in the product photo, this finish is not a glossy mirror like Black Nickel.
It is a Satin / Dark Charcoal industrial finish.
We can achieve this coating by applying a standard Zinc plate followed by a black chromate passivation layer.
This non-reflective coating is ideal for hiding magnets inside devices.
It still provides the excellent conductivity and glue adhesion of standard Zinc.
Why Black Zinc?
If you need a black magnet, you have three choices:
– Epoxy, Black Nickel, or Black Zinc.
Here is why you choose Zinc:
1. The “Adhesion” Champion:
The Problem:
Black Nickel is too slippery for many glues.
Black Epoxy is good, but thick.
The Solution:
Black Zinc retains the slightly porous, chemically active surface of standard Zinc.
It bonds aggressively with Cyanoacrylates (Super Glue) and Epoxies.
If you are gluing magnets into a black plastic housing and cannot afford “drop-outs,” this is the best black coating.
2. Non-Reflective “Stealth”:
The Application:
Sensors inside air vents, automotive interiors, or tactical gear.
The Logic:
Sometimes a shiny silver magnet reflects light through the gaps in a product casing.
Black Zinc absorbs light.
It allows the magnet to disappear visually into the background of dark components.
3. Cost Efficiency:
The Benefit:
Black Zinc is generally more cost-effective than Black Epoxy or Black Nickel.
This feature makes it a great choice for high-volume automotive or consumer electronic assemblies.
Manufacturing Specs: The Process
1. The Chromate Passivation:
The Chemistry:
The black color comes from a Trivalent Black Chromate conversion coating applied over the Zinc.
Corrosion Resistance:
This passivation layer significantly boosts the corrosion resistance compared to standard clear Zinc.
Offers extended protection against humidity (typically 24–72 hours Salt Spray).
2. Thickness:
The Spec: 8 – 12 Microns.
The Advantage:
It is much thinner than Epoxy (25+ microns).
Allows for tighter mechanical tolerances in your assembly.
Ideal Applications
Automotive Interiors: Magnets hidden behind dashboards or leather trim (non-reflective).
Consumer Electronics: Magnets glued inside black plastic remote controls or cases.
Tactical Equipment: Magnetic latches on gear where shine is unacceptable.
Speaker Assemblies: Magnets bonded to black frames.
Ordering Guide: Specifying the Finish
To ensure this is the right coating for you, please verify:
1). Appearance: “Is this a visible exterior part?”
Note:
Black Zinc is an industrial finish.
It may have slight color variations (iridescence) from batch to batch.
If you need “Jewelry Grade” perfection, choose Black Nickel.
2). Adhesion: “Will you be gluing this?” (Black Zinc is excellent for this).
3). Environment: “Is this for indoor or outdoor use?”
– For direct rain/salt exposure, we still recommend upgrading to Epoxy.
4). Dimensions: Shape and Size.
