Barrel Electro Coatings
fasteners nuts and bolts zinc plated and passivated
Zinc plated fasteners
Zinc plated fasteners are coated by the barrel electroplating process. This process creates a surface covering in which Zinc or another metal is deposited on a conductive steel surface. Electroplating is an old process and has been around for hundreds of years; it is critical for modern technology.
Barrel electroplating involves a chemical solution with the ionic form of the metal, an anode (positively charged) which may consist of the metal being plated or an insoluble anode and finally, a cathode (negatively charged) where electrons are supplied to produce a film of non-ionic metal.
Fastener Coating Benefits
Plating of fasteners is primarily for corrosion inhibition, also to improve the ability for the fastener to be:
- Surface hardened
- Improve wear life
- Reduce friction
- Improve paint adhesion
- Alter conductivity
- Give a decorative finish.
In addition to the Zinc protection against corrosion, a post-plating dip is applied to the zinc coating which is called a passivate or conversion coating.This additional process leaves a thin chromate film which screens the zinc from oxidizing.
The effectiveness of this two-layer system determines the overall corrosion performance of the coating.