A comparison of Geomet 500B and Delta Protekt KL120
posted 15th July 2026
Both Geomet 500B and Delta Protekt KL120 are highly regarded, non-electrolytic zinc flake coatings. They are primarily used on high-strength fasteners and steel components to provide exceptional cathodic corrosion protection without introducing the risk of hydrogen embrittlement.
The main structural difference lies in how lubrication is handled. Geomet 500B is a self-lubricating, water-based formulation, whereas Delta Protekt KL120 is an unlubricated, solvent-based base coat that requires a matching topcoat to manage friction.
Comparison of Key Technical Specifications
The table below breaks down the primary similarities and differences between the two coating technologies:
| TECHNICAL PROPERTY | GEOMET 500B | DELTA PROTEKT KL120 |
|---|---|---|
| Coating Type | Water-based zinc-aluminium flake. | Solvent-based zinc-aluminium flake base coat. |
| Lubrication Status | Self-lubricated: Features an integrated synthetic-oil-based lubricant. | Unlubricated: Requires a topcoat (such as Delta-Seal or VH300 series) for lubrication control. |
| Coefficient of Friction (µ) | 0.15+/-0.03 (consistent window measured via ISO 16047). | Highly variable on its own. Dependent on the selected topcoat to achieve specific windows (eg 0.09 to 0.15 or 0.12 to 0.18) |
| Corrosion Resistance (NSS) | Typically >=1,000 hours in Neutral Salt Spray (NSS) testing. | 240 to 1,100 hours depending on layers, or up to 1,000+ hours when combined with a topcoat. |
| Typical Layer Thickness | 5-15µm (8-12µm average for standard applications). | 2 to 4µm per layer. Commonly applied in multiple layers to reach 8 to 15µm total. |
| Baking / Curing Temperature | 300 to 320 deg C | 220 to 250 deg C |
| Hydrogen Embrittlement | None: The application process is completely non-electrolytic. | None: The non-electrolytic process eliminates hydrogen absorption. |
| Environmental Compliance | Free of hexavalent chromium (Cr6+) and other heavy metals. | Free of hexavalent chromium (Cr6+) and heavy metals (RoHS/REACH compliant). |
| Common Application Area | Structural fasteners (e.g., blind bolts), offshore marine equipment, and automotive components. | High-strength automotive fasteners, springs, clips, and safety washers. |
Key Operational Takeaways
1. Heat Sensitivity during Curing
Delta Protekt KL120 cures at a lower temperature range (220 to 250 deg C) compared to Geomet 500B (300-320 deg C). This lower curing temperature is highly advantageous for certain high-tensile, heat-sensitive spring steels, as it prevents thermal tempering or alterations to the metal structure.
2. Lubrication Strategy
Because Geomet 500B includes an integrated synthetic lubricant, it is an excellent "all-in-one" single-product solution. It provides a highly consistent and predictable friction coefficient straight out of the curing oven.
Delta Protekt KL120 relies on a modular "base coat plus topcoat" approach. While this requires an extra application step, it gives engineers the flexibility to customize chemical resistance, colour (such as silver or black), and friction characteristics to match unique automotive OEM specifications.