When it comes to protecting high-strength metal components, standard electro-zinc plating or heavy hot-dip galvanising eventually hit a wall. Traditional methods can introduce microscopic weaknesses, while heavy dipping can ruin the fine tolerances of precision parts.
Dacromet—a highly specialized, non-electrolytic zinc flake surface technology—replaces traditional methods by combining ultra-thin layers with brute-force corrosion resistance.
If you are manufacturing or specifying heavy-duty parts, automotive components, or high-grade fasteners, here is why Dacromet has become the global industrial standard.
Dacromet is not just a surface wrap; it is an inorganic coating composed of overlapping zinc and aluminum flakes bound together by a specialized matrix. This formulation gives it several distinct advantages:
1. Zero Hydrogen Embrittlement (The Fastener Lifesaver)
Traditional electroplating relies on acid pickling and an electrical current. This process inadvertently forces hydrogen ions into the metal matrix, causing high-strength steel bolts (Grade 10.9 and 12.9) to crack and snap unpredictably under tension. Because Dacromet is applied without electrolysis or acid, it eliminates the risk of hydrogen embrittlement entirely, making it the safest choice for critical load-bearing joints.
2. Extreme Salt Spray Endurance
Standard zinc plating offers about 200 to 300 hours of protection before red rust takes over. Despite being an incredibly thin layer (typically just 4 to 8 microns), a Dacromet coating withstands over 1,000 hours of neutral salt spray testing. That is up to 10 times the anti-rust performance of traditional options.
3. High Thermal Stability
Many defensive coatings peel, blister, or degrade when exposed to heat, rendering them useless in environments over 100°C. Dacromet remains completely stable and resists corrosion at continuous temperatures up to 300°C. This makes it perfectly suited for vehicle engine compartments, braking systems, and heavy industrial machinery.
4. Flawless Coverage on Mating Parts
Hot-dip galvanising leaves behind a rugged, thick, and uneven texture that easily clogs up internal threads. Dacromet is applied using a specialized dip-spin process. The liquid slurry flows evenly into deep recesses and fine thread pitches, then spins off excess material to guarantee a highly uniform matte-silver finish without ruining the part’s dimensions.
⚙️ How the Dip-Spin Process Works
Instead of floating ions onto the metal using electricity, the Dacromet technique relies on mechanical immersion and heat:
- Mechanical Cleaning: Metal parts are shot-blasted or degreased without harsh acids to completely clean the substrate.
- The Dip-Spin: Parts are placed into a mesh basket, submerged into the zinc-aluminum slurry, and spun at high speeds to centrifugally remove any excess coating.
- Curing: The parts are baked in industrial ovens at roughly 300°C to 320°C. This heat fuses the metallic flakes together into an incredibly dense, overlapping shield.
🏎️ Where is Dacromet Used?
Because it thrives where salt, heat, and structural stress collide, you will find Dacromet coatings widely utilized across several sectors:
- Automotive: Brake discs, calipers, leaf springs, and structural under-chassis fasteners.
- Renewable Energy: Wind turbine assembly bolts exposed to harsh offshore marine environments.
- Infrastructure: High-tension structural fasteners used in bridges, railways, and heavy construction.
If you require a quotation or technical assistance on Delta-Tone plated Non-Threaded Fasteners, please contact us today. Call + 44 (0)121 661 6664 or email us at sales@calebcomponents.com
Caleb Components – UK Supplier of Non-Threaded Fasteners in Delta-Tone (Dacromet) finish.