Solder & Low-Melting Alloy Sn99.9-CR (Cold rolled)
Supply condition
ASTM B339 Grade A · JIS H2112 Sn99.9
Rolled sheet, strip and foil for gaskets, capacitor foil, organ pipes and lining; tin self-anneals at room temperature so 'hard' tempers are not stable.
Values for the CR condition
Other Sn99.9 tempers and conditions
Sn99.9 is listed in 3 conditions; see the grade overview at Sn99.9.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As cast | Pick for cast tin anodes, tinning bar and decorative castings where no mechanical duty is required. | 8 | 14 | 40 | 4 HB | 15 % IACS |
Annealed | Fully soft condition (which pure tin reverts to at room temperature anyway) for maximum ductility in forming and wrapping. | 8 | 15 | 60 | 4 HB | 15 % IACS |
CRThis page Cold rolled | Rolled sheet, strip and foil for gaskets, capacitor foil, organ pipes and lining; tin self-anneals at room temperature so 'hard' tempers are not stable. | 11 | 20 | 55 | 5 HB | 15 % IACS |
What is Sn99.9-CR?
Sn99.9-CR is Sn99.9 supplied in the CR condition — rolled sheet, strip and foil for gaskets, capacitor foil, organ pipes and lining; tin self-anneals at room temperature so 'hard' tempers are not stable. Sn99.9-CR has a yield strength of 11 MPa (1.6 ksi) and a tensile strength of 20 MPa (2.9 ksi) — weaker than 90% of solder & low-melting alloy grades. Elongation at break is 55% and the elastic modulus is 44 GPa (6.38 Msi). Sn99.9-CR has a density of 7.29 g/cm³ (0.263 lb/in³), lighter than 96% of solder & low-melting alloy grades. It melts at 232°C (449 °F).
Advantages
- Conducts heat well — 66.6 W/m·K (38.5 BTU/hr·ft·°F), better than 98% of solder & low-melting alloy grades
- High electrical conductivity — 15 % IACS, better than 97% of solder & low-melting alloy grades
- Ductile — tolerates forming and impact — 55%, better than 96% of solder & low-melting alloy grades
- Lightweight — 7.29 g/cm³ (0.263 lb/in³), better than 96% of solder & low-melting alloy grades
- Good corrosion resistance — 65/100, better than 96% of solder & low-melting alloy grades
Limitations
- Low strength — 11 MPa (1.6 ksi), worse than 90% of solder & low-melting alloy grades
- High embodied carbon — 18 kg CO₂/kg, worse than 76% of solder & low-melting alloy grades
Sn99.9-CR properties
Typical room-temperature values for Sn99.9-CR; 18 are specific to this condition. Other listed values are Sn99.9 reference data and may not represent this condition. Bars are the position among solder & low-melting alloy grades.
Physical3
Sn99.9-CR has a density of 7.29 g/cm³ (0.263 lb/in³), lighter than 96% of solder & low-melting alloy grades. It melts at 232°C (449 °F).
Mechanical10
Sn99.9-CR has a yield strength of 11 MPa (1.6 ksi) and a tensile strength of 20 MPa (2.9 ksi) — weaker than 90% of solder & low-melting alloy grades. Elongation at break is 55% and the elastic modulus is 44 GPa (6.38 Msi).
Thermal6
Sn99.9-CR is rated for continuous service to 100°C (212 °F). It conducts heat at 66.6 W/m·K (38.5 BTU/hr·ft·°F), better than 98% of solder & low-melting alloy grades. Thermal expansion is 23 µm/m·K (12.8 µin/in·°F).
Electrical3
Sn99.9-CR conducts electricity at 15 % IACS, better than 97% of solder & low-melting alloy grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 96% of solder & low-melting alloy grades.
Sustainability4
Producing a kilogram of Sn99.9-CR takes about 320 MJ of energy and emits 18 kg of CO₂ — more than 81% of solder & low-melting alloy grades. Typical recycled content is 30%.
Manufacturability8
Sn99.9-CR's machinability is fair (45/100, better than 69% of solder & low-melting alloy grades); weldability fair (40/100); formability excellent (95/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Sn99.9-CR
Is Sn99.9 easy to machine?
Very soft and gummy — use sharp high-rake tools, high speed, light feed and generous lubrication or freeze/chill the part to avoid smearing.
Can Sn99.9 be welded?
Rarely fusion welded; joints are made by soldering or by simply remelting since the metal itself is the solder base — keep away from sulfur and avoid overheating (dross formation).
Can Sn99.9 be formed, bent or molded?
Rolls to foil and cold-forms almost without limit because it recrystallizes at room temperature; casts easily at 250–300 °C with low shrinkage but poor as-cast strength.
What surface finishes work on Sn99.9?
Bright but easily scratched; can be burnished, tumbled or lightly buffed. Not anodizable; typically used as-plated/tinned or given a light passivation to avoid dulling and whisker growth.
Sn99.9 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance.
| Element | Spec limit (wt %) |
|---|---|
| Pbimpurity limit | ≤ 0.05 |
| Sbimpurity limit | ≤ 0.05 |
| Biimpurity limit | ≤ 0.03 |
| Asimpurity limit | ≤ 0.03 |
| Cuimpurity limit | ≤ 0.03 |
| Feimpurity limit | ≤ 0.01 |
| Znimpurity limit | ≤ 0 |
| Alimpurity limit | ≤ 0 |
| Cdimpurity limit | ≤ 0 |
| Simpurity limit | ≤ 0.01 |
| Total impuritiessum of impurities | ≤ 0.1 |
| SnGB/T 728 Sn99.90 / ASTM B339 Grade A | ≥ 99.9 (balance) |
Sn99.9-CR — frequently asked
What is Sn99.9-CR used for?
Sn99.9-CR is typically used for alloy feedstock, tin plating anodes, chemical tin salts and babbitt/pewter melting stock. In short: purest tin feedstock; corrosion-resistant, low melting point; softest alloy in the family.
What is the yield strength of Sn99.9-CR?
Sn99.9-CR has a typical yield strength of 11 MPa (1.6 ksi) and a tensile strength of 20 MPa (2.9 ksi) — weaker than 90% of solder & low-melting alloy grades. Strength varies by condition: see the 3 listed tempers.
Is Sn99.9-CR easy to machine?
Reasonably — machinability is rated fair (45/100, better than 69% of solder & low-melting alloy grades). Very soft and gummy — use sharp high-rake tools, high speed, light feed and generous lubrication or freeze/chill the part to avoid smearing.
Can Sn99.9-CR be welded?
With care — weldability is rated fair (40/100). Rarely fusion welded; joints are made by soldering or by simply remelting since the metal itself is the solder base — keep away from sulfur and avoid overheating (dross formation).
What surface finishes work on Sn99.9-CR?
Bright but easily scratched; can be burnished, tumbled or lightly buffed. Not anodizable; typically used as-plated/tinned or given a light passivation to avoid dulling and whisker growth.
Can Sn99.9-CR be formed, bent or molded?
Rolls to foil and cold-forms almost without limit because it recrystallizes at room temperature; casts easily at 250–300 °C with low shrinkage but poor as-cast strength.
What is the maximum service temperature of Sn99.9-CR?
Sn99.9-CR is rated for continuous use to about 100°C (212 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- GB/T 728 — SAC (2020)
- ASTM B339 Standard Specification for Pig Tin — ASTM International (2022)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (Tin and Tin Alloys) — ASM International (1990)
- CRC Handbook of Chemistry and Physics — Properties of the Elements — CRC Press (2022)
- International Tin Association / ITRI tin property data — ITA (2021)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.