Surface Treatments & Corrosion Performance for Fasteners
Surface treatments for fasteners can be divided into three main categories: aesthetic finishes, protective coatings, and functional coatings.
While aesthetic treatments are mainly used to improve appearance, protective coatings are designed to enhance corrosion resistance, and functional coatings play a critical role in controlling friction, tightening behaviour, and overall assembly performance.
Choosing the correct surface treatment is not only a matter of protection, but directly affects the reliability, durability, and performance of the fastening system.
Aesthetic Finishes
Aesthetic finishes are primarily used to improve the visual appearance of fasteners.
They provide a uniform look and can enhance surface appearance, but offer limited corrosion protection. These treatments are typically used in non-critical indoor applications where appearance is more important than performance.
Examples include black oxide and decorative coatings.
Protective Coatings
Protective coatings are primarily used to prevent corrosion and extend the service life of fasteners.
They create a barrier between the base material and the environment and are selected based on exposure conditions and required durability.
Typical solutions include:
Zinc plating
Zinc-nickel coatings
Hot dip galvanizing
Zinc flake systems (e.g. GEOMET®)
Functional Coatings
Functional coatings improve fastening performance during assembly and service.
They control friction, prevent loosening, and ensure reliable sealing in critical applications.
Typical solutions include:
Pre-applied threadlockers
Sealants for threaded connections
Self-locking patches
Low-friction coatings (e.g. PTFE)
The selection of the correct surface treatment depends on:
required corrosion resistance
assembly conditions and friction requirements
mechanical properties of the fastener
application environment
For specific applications, a technical evaluation is recommended.
Contact us for technical support.