From Concept to Production. Built for Brands.
Living Patina & Precision Dials
Custom Brass & Marine Bronze Precision Manufacturing
Engineered copper alloys encompassing lead-free dial-grade brass (H62 / CW510L) and authentic marine phosphor bronze (CuSn8). Designed for vintage maritime tool watches that develop rich, unique surface patinas, alongside micro-machined watch dials, movement spacers, and sculptural desk decor.
Material Benchmark
- Bronze Alloy Grade German Standard CuSn8 (UNS C52100 / CW453K)
- Dial Brass Grade H62 / CW510L Environmental Low-Lead Brass
- Bronze Composition 91-92% Copper, 7.5-8.5% Tin, 0.01-0.4% Phosphorus
- Oxidation Dynamics Forms protective cuprous oxide & malachite patina
- Vickers Hardness (Bronze) 150 to 190 HV cold rolled
- Dial Blank Flatness Within 0.005 mm across 35 mm dial span
- Turning Machinability Class 100 high-speed chip breaking
- Seawater Endurance Immune to biofouling & marine pitting
Technical Scope
Copper Alloy Applications & Metallurgy
From vintage diver cases with evolving surface patinas to micro-thin precision guilloché dials.
Marine Horology
CuSn8 Marine Phosphor Bronze
Solid CuSn8 bronze bar stock CNC machined into diver watch cases and rotating bezels. Reacts naturally with ambient moisture and skin oils to produce an organic antique patina.
- Tin Content 8.0% tin imparts mechanical springiness
- Patina Velocity Natural aging over 3 to 12 months
- Caseback Barrier Paired with titanium caseback to prevent skin stains
Watch Dial Substrates
Precision Micro-Brass Blanks
Ultra-flat brass discs engineered for stamping, sunburst radial brushing, laser cut apertures, enamel coating, and multi-layer pad printing.
- Blank Thickness 0.40 mm down to 0.18 mm
- Substrate Flatness Zero bowing across movement feet
- Plating Affinity Superior adhesion for rhodium & gold plating
Internal Movement Spacers
Structural Brass Movement Rings
Precision turned and milled movement casing rings that securely mount mechanical calibers within outer cases, damping vibrations and holding exact stem heights.
- Concentricity Within 0.003 mm runout
- Surface Treatment Electroless nickel or 24K gold flash
- Mounting Screws Precision tapped micro-threads
Material Benchmarks
Brass vs CuSn8 Bronze Comparative Engineering Data
Strict chemical composition limits and mechanical standards applied across every production batch.
| Alloy Parameter | H62 Precision Brass | CuSn8 Phosphor Bronze | Engineering Significance |
|---|---|---|---|
| Copper Content (Cu) | 60.5% to 63.5% | 91.5% to 92.5% | CuSn8 possesses significantly higher copper purity and density |
| Alloy Elements | 36% Zinc, Trace Pb < 0.05% | 8.0% Tin (Sn), 0.15% Phosphorus (P) | Tin provides spring elasticity and superior salt resistance |
| Density (g/cm³) | 8.50 g/cm³ | 8.80 g/cm³ | CuSn8 offers a heavier, more luxurious wrist presence |
| Corrosion Response | Forms dull brownish tarnish | Forms dense, beautiful greenish-brown patina | Bronze patina seals the alloy against deeper environmental degradation |
| Primary Use | Watch dials, hands, decorative pens | Diver cases, nautical bezels, heavy buckles | Dedicated application based on mechanical and aesthetic needs |
Manufacturing Protocol
Precision Processing Workflow
From raw ingot spectral audit to cleanroom quality inspection, our engineering workflow ensures strict metallurgical repeatability.
PHASE 01
Raw Stock Spectrometry Audit
Incoming billets undergo handheld XRF spectral testing and optical emission analysis to confirm chemical composition and low carbon/gas content before sawing.
PHASE 02
Multi-Axis CNC Machining
Components are machined on high-rigidity Japanese 5-axis machining centers with high-pressure synthetic flood coolant to prevent work hardening and surface micro-tears.
PHASE 03
Artisanal Finishing & Lapping
Components undergo specialized compound buffing, satin graining, and diamond micro-lapping to create distortion-free optical mirror bevels and crisp transition lines.
PHASE 04
Passivation & Biocompatibility QC
Finished components undergo automated ultrasonic degreasing, chemical passivation, and salt-spray testing to verify hypoallergenic skin contact performance.
Technical Guidance
Frequently Asked Questions
Common technical and manufacturing questions regarding this material grade, tooling requirements, and finishing capabilities.
How does CuSn8 bronze develop its patina over time?
CuSn8 contains 8% tin and over 91% copper. When exposed to ambient oxygen, humidity, and atmospheric sulfides, it naturally forms a stable thin layer of copper oxide and copper carbonate (malachite). This protects the core metal while giving every timepiece a unique vintage character.
Does a bronze watch turn the wearer’s skin green?
Direct, prolonged contact between bronze and acidic sweat can cause temporary skin discoloration. To eliminate this, our bronze watch engineering mandates a hypoallergenic Grade 5 titanium or 316L stainless steel caseback, so only skin-neutral metal contacts the wrist.
Can Fullion pre-age or accelerate patina on bronze cases?
Yes. We can deliver bronze cases with freshly machined bright gold-copper luster, or apply controlled chemical vapor treatments (liver of sulfur) to deliver uniform vintage antique patinas upon request.
What brass grades do you use for dials and decorative accessories?
We strictly utilize environmentally certified lead-free brass (CW510L / H62) compliant with California Proposition 65 and RoHS, ensuring safe wear and crisp laser micro-milling.
Start Your Production Project
Bring Horological Precision to Your Decor Line
Send us your 3D concept designs, component blueprints, or sample references. Our engineering desk will deliver an exhaustive DFM analysis, tooling budget, and quotation within 24 business hours.
Submit Request for Quotation