The retention clip is the most overlooked component in a braking system. It is also one of the most critical — especially in the automotive aftermarket, where the variety of applications and operational demands makes selecting the right coating a defining decision.
What is a retention clip and why does it matter?
The retention clip is the component responsible for keeping the brake pad firmly positioned within the braking system. Its function seems simple. The consequences when it fails are not.
A clip that fractures in service can cause the brake pad to detach during braking. That is not a surface quality issue — it is a direct safety risk for the driver and the vehicle.
To perform its function, the clip must be manufactured from high-hardness steel. And that is where the problem begins.
The problem: hydrogen embrittlement in high-hardness components
High-hardness steels are especially susceptible to a phenomenon known as hydrogen embrittlement.
When a high-hardness component is subjected to conventional electrolytic zinc plating, the hydrogen generated during electrodeposition penetrates the microstructure of the steel. This creates internal stresses and microcracks that are not visible to the naked eye.
The problem does not end there. These fractures do not necessarily occur during the process — they can appear days or weeks later, under sustained load, in real operating conditions. This is known as delayed fracture.
Many manufacturers apply a post-plating hydrogen relief treatment to try to reverse this effect. But that treatment is not always sufficient. In components with complex geometry like retention clips — with tight bends, edges, and hard-to-reach areas — complete hydrogen removal is not guaranteed.
The result: a component that passes quality control but carries an internal risk that only reveals itself in service.
Why conventional zinc plating is not enough for retention clips
Electrolytic zinc plating is widely used in the automotive industry. For many applications, it works well. For high-hardness retention clips, it represents a risk that cannot be ignored.
Three factors combine to make it especially critical in this component:
High material hardness. The harder the steel, the greater the susceptibility to hydrogen embrittlement. Retention clips operate in the hardness range where this phenomenon is most severe.
Complex geometry. The bends, edges, and contact surfaces of the clip make both uniform coating application and effective hydrogen removal during relief treatment more difficult.
Sustained load in service. The clip works under constant tension within the braking system. That sustained load is exactly the condition that triggers delayed hydrogen fractures.
All three factors present at the same time, in the same component.
What a coating for retention clips must deliver
To properly protect a retention clip without compromising its mechanical integrity, the coating must meet three non-negotiable conditions:
Non-electrolytic process. Eliminates from the outset any possibility of introducing hydrogen into the steel. There is no risk to manage because the risk never exists.
Acid-free pretreatment. The acids used in surface preparation for conventional processes can also introduce hydrogen before the coating is applied. An acid-free pretreatment protects the steel microstructure from the very first stage of the process.
Uniform coverage on complex geometries. The coating must cover bends, edges, and hard-to-reach areas homogeneously — the same areas where hydrogen tends to concentrate and where the fracture risk is highest.
Laurentcoat®, the zinc flake coating developed and applied by Chousa, meets all three conditions. Its dip spin application process with thermal curing completely eliminates the risk of hydrogen embrittlement, protects the steel microstructure from the pretreatment stage, and guarantees uniform coverage even on the most complex geometries.
Do you manufacture or specify retention clips for brake pads?
Hydrogen embrittlement is a real, silent, and preventable risk. The good news is that the problem has a solution: non-electrolytic coatings like Laurentcoat® eliminate the risk from the origin, without compromising corrosion resistance or the dimensional precision of the components.
Do you want to evaluate whether your current retention clip coating represents a risk in your process?
Contact us at info@chousa.com.ar and connect with our technical team.
