Solder & Low-Melting Alloy Ga68In20Sn12
also Galinstan
Ga68In20Sn12 (Galinstan) is a eutectic gallium-indium-tin alloy that is liquid at room temperature, with a melting point of about -19 °C, and is stocked in 3N, 4N and 5N purity grades.
Reference datasheet — Ga68In20Sn12 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the 4N condition
Ga68In20Sn12 tempers and conditions
Ga68In20Sn12 is supplied in 3 conditions, soft to hard. 4N is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
4NDefault 99.99 % purity liquid alloy | Default stock grade for thermometers, thermal interface, liquid-metal cooling and lab/flexible-electronics use. | 6 % IACS | ||||
99.9 % industrial/bulk grade | Lowest-cost bulk grade for heat-transfer loops, dampers and switches where trace impurities do not matter. | 5.8 % IACS | ||||
99.999 % high-purity / semiconductor-grade | Choose for electrochemistry, EGaIn junction research and semiconductor-adjacent work where alkali/heavy-metal traces are critical. | 6 % IACS |
What is Ga68In20Sn12?
Ga68In20Sn12 (Galinstan) is a eutectic gallium-indium-tin alloy that is liquid at room temperature, with a melting point of about -19 °C, and is stocked in 3N, 4N and 5N purity grades. Engineers specify it as a non-toxic replacement for mercury in thermometers and as a liquid-metal conductor, thermal interface or coolant, dispensed by syringe, printed, or sealed in glass or fluoropolymer capillaries. Limits are practical rather than mechanical: it wets and embrittles aluminium alloys, carries a Ga2O3 skin that must be stripped for clean flow, and conducts only 6 % IACS electrically and 16.5 W/m·K thermally, with a stated maximum service temperature of 200 °C. Where a solid low-melting metal is acceptable, a bismuth-based fusible alloy is the usual alternative. Ga68In20Sn12 has a density of 6.44 g/cm³ (0.233 lb/in³), lighter than 100% of solder & low-melting alloy grades. It melts at -19°C (-2 °F).
What is Ga68In20Sn12 used for?
- mercury-free thermometers
- liquid metal cooling
- flexible/stretchable electronics
- vacuum seals and manometers
Advantages
- Lightweight — 6.44 g/cm³ (0.233 lb/in³), better than 100% of solder & low-melting alloy grades
- High service temperature — 200°C (392 °F), better than 99% of solder & low-melting alloy grades
Limitations
- High embodied carbon — 170 kg CO₂/kg, worse than 100% of solder & low-melting alloy grades
- Poor heat conductor — 16.5 W/m·K (9.53 BTU/hr·ft·°F), worse than 96% of solder & low-melting alloy grades
- Low electrical conductivity — 6 % IACS, worse than 84% of solder & low-melting alloy grades
Ga68In20Sn12 properties
Typical room-temperature values for Ga68In20Sn12-4N; bars are the position among solder & low-melting alloy grades.
Physical3
Ga68In20Sn12 has a density of 6.44 g/cm³ (0.233 lb/in³), lighter than 100% of solder & low-melting alloy grades. It melts at -19°C (-2 °F).
Mechanical1
Thermal5
Ga68In20Sn12 is rated for continuous service to 200°C (392 °F). It conducts heat at 16.5 W/m·K (9.53 BTU/hr·ft·°F), worse than 96% of solder & low-melting alloy grades. Thermal expansion is 38 µm/m·K (21.1 µin/in·°F).
Electrical3
Ga68In20Sn12 conducts electricity at 6 % IACS, worse than 84% of solder & low-melting alloy grades.
Chemical & Environmental2
Corrosion resistance is fair (50/100), better than 70% of solder & low-melting alloy grades.
Sustainability3
Producing a kilogram of Ga68In20Sn12 takes about 2,500 MJ of energy and emits 170 kg of CO₂ — more than 100% of solder & low-melting alloy grades. Typical recycled content is 30%.
Common Calculations1
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the solder & low-melting alloy family
Yield strength against density for every solder & low-melting alloy grade FabDigit runs. Ga68In20Sn12 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Ga68In20Sn12
Is Ga68In20Sn12 easy to machine?
Not machinable — the alloy is liquid at room temperature; 'processing' means dispensing, syringe/needle injection or printing, and it will alloy with and embrittle any aluminium tooling it contacts.
Can Ga68In20Sn12 be welded?
Not weldable; joints are made by containing the liquid — use PTFE/PFA, PEEK or glass tubing with fluoroelastomer or metal-free seals, and tungsten/graphite or 316L electrodes for electrical contact.
Can Ga68In20Sn12 be formed, bent or molded?
Cast/inject into elastomer (PDMS, TPU) microchannels or fill capillaries; the Ga2O3 skin gives an apparent yield stress that helps pattern-printing but must be removed with dilute HCl or NaOH for clean flow and wetting.
Ga68In20Sn12 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. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| In21.5 % in the classic Galinstan formulation | 19 – 22 | 20 |
| Sn10 % in the classic Galinstan formulation | 10 – 13 | 12 |
| Other, each4N grade; total impurities ≤0.01 % | ≤ 0.01 | |
| Gabalance, ~68–68.5 % | balance |
What surface finishes work on Ga68In20Sn12?
No plating or anodizing applies; surfaces it contacts should be pre-passivated or oxide-stripped, and spills are cleaned with dilute HCl/NaOH — keep it away from aluminium alloys entirely.
Equivalent designations
Standards and trade names that resolve to Solder & Low-Melting Alloy Ga68In20Sn12 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Galinstan
How much does Ga68In20Sn12 cost?
Ga68In20Sn12 is a high-cost solder & low-melting alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Ga68In20Sn12 — frequently asked
What is Ga68In20Sn12 used for?
Ga68In20Sn12 is typically used for mercury-free thermometers, liquid metal cooling, flexible/stretchable electronics and vacuum seals and manometers. In short: liquid at room temperature; mercury-free thermometer fluid; attacks aluminium tooling.
Is Ga68In20Sn12 easy to machine?
Not machinable — the alloy is liquid at room temperature; 'processing' means dispensing, syringe/needle injection or printing, and it will alloy with and embrittle any aluminium tooling it contacts.
Can Ga68In20Sn12 be welded?
Not weldable; joints are made by containing the liquid — use PTFE/PFA, PEEK or glass tubing with fluoroelastomer or metal-free seals, and tungsten/graphite or 316L electrodes for electrical contact.
What surface finishes work on Ga68In20Sn12?
No plating or anodizing applies; surfaces it contacts should be pre-passivated or oxide-stripped, and spills are cleaned with dilute HCl/NaOH — keep it away from aluminium alloys entirely.
Can Ga68In20Sn12 be formed, bent or molded?
Cast/inject into elastomer (PDMS, TPU) microchannels or fill capillaries; the Ga2O3 skin gives an apparent yield stress that helps pattern-printing but must be removed with dilute HCl or NaOH for clean flow and wetting.
What is the maximum service temperature of Ga68In20Sn12?
Ga68In20Sn12 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Ga68In20Sn12 cost?
Ga68In20Sn12 is a high-cost solder & low-melting alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- Galinstan liquid metal alloy datasheet — Geratherm Medical AG (2020)
- Galinstan (Ga-In-Sn) product data — Rotometals (2023)
- Properties of liquid gallium alloys — thermophysical and transport data — ASM International / Journal of Nuclear Materials compilations (2008)
- Ga-In-Sn ternary phase diagram and eutectic data — ASM Alloy Phase Diagram Database (2016)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.