Commercial Tin in the 99.5% to 99.8% purity range represents standard industrial-grade refined tin. It is primarily used where cost efficiency, alloying performance, and basic corrosion resistance are more important than ultra-high chemical purity.
This grade is commonly used as a feedstock material rather than a finished product.
Basic Identification
| Property | Value |
|---|---|
| Purity Range | 99.5% – 99.8% Sn |
| Allotropic Form | β-Tin (White Tin) |
| Crystal Structure | Body-Centered Tetragonal (BCT) |
| Standards Reference | ASTM B339, ISO 21948, EN 610 |
Typical Chemical Composition
| Element | Approx. Content (%) |
|---|---|
| Tin (Sn) | 99.5 – 99.8 |
| Lead (Pb) | 0.10 – 0.30 |
| Antimony (Sb) | 0.05 – 0.20 |
| Copper (Cu) | 0.01 – 0.10 |
| Iron (Fe) | 0.01 – 0.05 |
| Bismuth (Bi) | ≤ 0.05 |
| Arsenic (As) | ≤ 0.05 |
Mechanical Properties
| Property | Typical Value |
|---|---|
| Tensile Strength | 18 – 30 MPa |
| Yield Strength | Very low |
| Elongation | 20 – 35% |
| Hardness | ~8 – 12 HV |
| Ductility | Good |
| Creep Resistance | Slightly better than high-purity tin |
Physical Properties
| Property | Value |
|---|---|
| Density | ~7.30 g/cm³ |
| Melting Point | 231 – 232 °C |
| Electrical Conductivity | ~13 – 14% IACS |
| Thermal Conductivity | ~60 – 65 W/m·K |
| Magnetic Behavior | Diamagnetic |
| Appearance | Silvery-white to dull gray |
Strengthening & Metallurgical Behavior
Commercial tin is not heat treatable. Strengthening occurs through solid-solution effects from lead, antimony, and copper, along with minor work hardening.
Compared to ultra-pure tin, this grade exhibits reduced tin whisker growth tendency and improved microstructural stability, though with reduced corrosion resistance.
Key Characteristics
✔ Economical and widely available
✔ Excellent melting and casting behavior
✔ Suitable for alloying and foundry use
✔ Improved creep resistance vs pure tin
✔ Stable handling characteristics
❌ Not suitable for precision electronics
Refining & Processing
Commercial tin is produced by smelting and fire refining with limited impurity control. Full electrolytic refining is not applied, keeping production costs low and ensuring consistent industrial-grade quality.
| Process | Performance |
|---|---|
| Melting | Excellent |
| Casting | Excellent |
| Rolling | Fair |
| Machining | Poor |
| Solderability | Moderate |
Available Forms
Tin ingots / pigs
Tin blocks
Granulated tin
Alloy feedstock
Scrap-derived refined tin
Applications
🏭 Bronze, Babbitt, and foundry alloys
⚡ Low-grade solders and cable sheathing
🏗 Float glass manufacturing
🧪 Chemical catalysts and industrial coatings
Advantages
✔ Lowest cost among refined tin grades
✔ Excellent alloying efficiency
✔ Easy melting and casting
✔ Stable global supply
Limitations
❌ Not food-grade
❌ Not RoHS compliant in many cases
❌ Not suitable for aerospace or medical use
❌ Impurity-driven corrosion risk in harsh environments
Commercial Tin vs Higher Grades
| Feature | Commercial (99.5–99.8%) | Grade C (99.90%) | Grade A (99.99%) |
|---|---|---|---|
| Purity | Moderate | High | Ultra-high |
| Cost | Lowest | Medium | Highest |
| Electronics Use | Poor | General | Critical |
| Alloying Use | Excellent | Excellent | Excellent |
| Whisker Risk | Low | Lower | Higher |
Why Choose Commercial Tin?
Commercial Tin (99.5% – 99.8%) is selected when volume, economy, and alloy performance matter more than purity. It delivers excellent processability and cost efficiency for industrial, foundry, and non-critical electrical applications.