Refined silver bars are fully purified silver products produced by accredited refineries or mints, containing very high silver purity with tightly controlled trace impurities. Unlike silver doré bars, refined silver bars require no further metallurgical processing before use.
They are intended for investment and wealth preservation, industrial and technological applications, and central bank or institutional holdings.
Purity & Grade Classification
| Grade Name | Silver Content | Fineness |
|---|---|---|
| Investment Grade | ≥ 99.9% Ag | 999 |
| High-Purity Grade | ≥ 99.99% Ag | 999.9 |
| Ultra-High Purity | ≥ 99.999% Ag | 999.99 |
✔ 999 fine silver is the global bullion standard
✔ 999.9 silver is widely used for electronics and specialty applications
Chemical Composition
| Element | Typical Content |
|---|---|
| Silver (Ag) | 99.9 – 99.99% |
| Copper (Cu) | < 0.05% |
| Gold (Au) | Trace (ppm) |
| Lead (Pb) | < 0.01% |
| Zinc (Zn) | Trace |
| Sulfur / Selenium | Trace |
Refined silver bars are chemically homogeneous and produced under strict assay control.
Key Physical Properties
| Property | Typical Value |
|---|---|
| Density | 10.49 g/cm³ |
| Melting Point | 961.8 °C |
| Thermal Conductivity | ~430 W/m·K |
| Electrical Conductivity | ~105% IACS |
| Reflectivity | ~95% |
| Magnetic Behavior | Non-magnetic |
| Corrosion Resistance | Excellent (tarnishes in sulfur environments) |
Mechanical Properties
| Property | Typical Value |
|---|---|
| Hardness (Annealed) | 25 – 30 HV |
| Tensile Strength | ~170 MPa |
| Yield Strength | ~55 MPa |
| Elongation | > 40% |
| Brittleness | Very low |
Softness is inherent to high-purity silver and is not a defect in bullion products.
Metallurgical Characteristics
• Face-centered cubic (FCC) crystal structure
• Single-phase silver matrix
• Extremely low impurity levels
• No phase segregation or precipitation
High purity is prioritized over mechanical strength. Only minor work hardening is possible.
Refining & Manufacturing Process
Refining Routes:
• Electrorefining (primary method)
• Chemical dissolution and purification
• Zone refining for ultra-high purity silver
Manufacturing Steps:
Doré refining → electro-purification → controlled melting → casting or minting →
weighing & assaying → hallmarking
Available Forms & Sizes
By Manufacturing Type
✔ Cast bars (lower premium, industrial use)
✔ Minted bars (smooth finish, sealed packaging)
Common Sizes
10 g – 100 g (retail)
250 g – 1 kg (investment)
5 kg – 15 kg (LBMA Good Delivery)
1,000 oz (COMEX)
Applications
Investment: Wealth preservation, inflation hedge, portfolio diversification
Industrial: Electronics, semiconductors, solar PV, electrical contacts, conductive pastes
Monetary & Institutional: Central bank reserves, ETFs, vault storage
Advantages
✔ Highest electrical and thermal conductivity of all metals
✔ Globally recognized bullion form
✔ High liquidity and tradability
✔ Easy storage and transport
✔ Fully recyclable
Limitations
⚠ Softer than alloyed silver
⚠ Tarnishes in sulfur-rich environments
⚠ Larger bars less divisible
⚠ Requires secure storage
Refined Silver Bars vs Other Silver Forms
| Feature | Refined Bar | Doré Bar | Silver Coin |
|---|---|---|---|
| Purity | ≥ 99.9% | 50 – 98% | 90 – 99.9% |
| Refining Needed | No | Yes | No |
| Investment Grade | ✔ | ❌ | ✔ |
| Surface Finish | Smooth / Cast | Rough | Minted |
| Liquidity | High | Refinery-only | Very high |
Why Choose Refined Silver Bars
Refined silver bars are chosen when maximum purity, long-term ownership, industrial feedstock quality, and global tradability are essential. They form the foundation of the global silver investment market and are critical raw materials for modern electronics, renewable energy, and advanced technologies.