FabDigit

Solder & Low-Melting Alloy Ga68In20Sn12 3N

Grade

also Galinstan

3N = 99.9 % industrial/bulk grade

Lowest-cost bulk grade for heat-transfer loops, dampers and switches where trace impurities do not matter.

High cost $$$$
Get a quoteGa68In20Sn12 overview

Values for the 3N condition

Other Ga68In20Sn12 tempers and conditions

Ga68In20Sn12 is listed in 3 conditions; see the grade overview at Ga68In20Sn12.

Compare all 3 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
4NDefault
99.99 % purity liquid alloy
Default stock grade for thermometers, thermal interface, liquid-metal cooling and lab/flexible-electronics use.6 % IACS
3NThis page
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
5N
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 3N?

Ga68In20Sn12 3N is Ga68In20Sn12 in the 3N grade — lowest-cost bulk grade for heat-transfer loops, dampers and switches where trace impurities do not matter. Ga68In20Sn12 3N 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). 4N is the default condition FabDigit quotes; 3N is available on request or by drawing note.

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 — 5.8 % IACS, worse than 86% of solder & low-melting alloy grades

Ga68In20Sn12 3N properties

Typical room-temperature values for Ga68In20Sn12 3N; 5 are specific to this condition. Other listed values are Ga68In20Sn12 reference data and may not represent this condition. Bars are the position among solder & low-melting alloy grades.

Physical3

Ga68In20Sn12 3N 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).

Density6.44 g/cm³0.23 lb/in³
Melting Point (Solidus)-19°C-2 °F
Liquidus Temperature-19°C-2 °F

Mechanical1

Bulk Modulus48 GPa7 Msi

Thermal5

Ga68In20Sn12 3N 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).

Thermal Conductivity16.5 W/m·K9.5 BTU/hr·ft·°F
Specific Heat Capacity296 J/kg·K0.07 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)38 µm/m·K21.1 µin/in·°F
Max Service Temperature (continuous)200°C392 °F
Min Service Temperature-19°C-2 °F

Electrical3

Ga68In20Sn12 3N conducts electricity at 5.8 % IACS, worse than 86% of solder & low-melting alloy grades.

Electrical Conductivity5.8 % IACS
Electrical Resistivity2.95×10⁻⁷ Ω·m11.6 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental2

Corrosion resistance is fair (45/100), worse than 52% of solder & low-melting alloy grades.

Corrosion ResistanceFair45/100
Chemical Resistance SummaryInstantly forms a thin Ga2O3 skin in air that makes it adhere to most surfaces; stable against water and most non-oxidising media. Aggressively wets, dissolves and embrittles Al, Zn, Cu, Ag, Au, Ni and common solders; attacks glass only slowly but wets it once the oxide is disturbed. Compatible containment: PTFE/PFA, PEEK, most fluoropolymers, borosilicate glass, quartz, alumina, graphite, tungste

Sustainability3

Producing a kilogram of Ga68In20Sn12 3N 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%.

Embodied Energy (primary production)2,500 MJ/kg1,074,808 BTU/lb
Embodied Carbon (primary production)170 kg CO₂/kg
Typical Recycled Content30%

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with Ga68In20Sn12 3N

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.

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.

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.

ElementSpec limit (wt %)Nominal
In21.5 % in the classic Galinstan formulation19 – 2220
Sn10 % in the classic Galinstan formulation10 – 1312
Other, each4N grade; total impurities ≤0.01 %≤ 0.01
Gabalance, ~68–68.5 %balance

Ga68In20Sn12 3N — frequently asked

What is Ga68In20Sn12 3N used for?

Ga68In20Sn12 3N 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 3N 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 3N 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 3N?

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 3N 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 3N?

Ga68In20Sn12 3N 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.

Sources

  1. Galinstan liquid metal alloy datasheet — Geratherm Medical AG (2020)
  2. Galinstan (Ga-In-Sn) product data — Rotometals (2023)
  3. Properties of liquid gallium alloys — thermophysical and transport data — ASM International / Journal of Nuclear Materials compilations (2008)
  4. 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.