Polished Brass (US3 / PB): Mirror Buffing and High-Hardness Zirconium PVD
Engineering Overview: Technical comparison of traditional lacquered Polished Brass (US3) versus Zirconium PVD Gold for architectural lock cylinders.
Technical & Engineering Specifications
| Hardness | 2400 HV (PVD) vs 120 HV (Lacquered Brass) |
|---|---|
| Salt Spray | ASTM B117 > 1000 hours (PVD) |
| UV Stability | 100% Impervious to Solar Degradation |
| Finish Standard | Polished Brass (US3) vs Zirconium PVD (ZrN) |
| Surface Roughness | Ra < 0.05 um Mirror Luster |
Mirror Gold Finish Engineering
Polished Brass (US3 / BHMA 605) represents the timeless mirror-gold standard in classical architectural hardware.
Traditional Lacquer vs. Zirconium PVD
- Traditional US3 Lacquered: Hand-buffed to Ra < 0.05 μm mirror luster and sealed with lacquer. Susceptible to UV degradation and scratch marks within 2 years.
- Zirconium PVD Gold (ZrN): Vacuum deposited ceramic layer with 2400 HV hardness and ASTM B117 > 1000 hours salt spray resistance, offering a lifetime non-tarnish architectural warranty.
Frequently Asked Engineering & Selection Questions
Q1: Why choose Zirconium PVD over traditional polished brass?
Zirconium PVD creates an ultra-hard (2400 HV) ceramic layer that never tarnishes, scratches, or discolors under outdoor sunlight.