Lead-freeLead-Free and Cadmium-Free144°F Eutectic Melt PointExcellent Wetting PropertiesMercury Alternative
Lead-free eutectic alloy (32.5% Bi, 51% In, 16.5% Sn) melting at 144°F (62°C). Non-toxic mercury alternative for liquid metal cooling, vacuum sealing, and R&D applications.
Field’s Metal is a bismuth-indium-tin eutectic alloy with a nominal composition of 32.5% Bi, 51% In, and 16.5% Sn, melting sharply at 144°F (62°C). Named after its inventor Simon Quellen Field, this alloy melts just above the boiling point of water, making it one of the lowest-melting lead-free and cadmium-free alloys in this class. Density is approximately 0.285 lbs/in (7.88 g/cm). The lead-free and cadmium-free composition makes Field’s Metal a significantly less toxic alternative to Wood’s Metal and other traditional cadmium-bearing fusible alloys, while its very low melting point enables casting in plastic molds, silicone rubber molds, and delicate substrates that cannot withstand higher temperatures. The high indium content (over 51%) provides excellent wetting properties — Field’s Metal wets glass, ceramics, and many metals that standard low melting alloys do not adhere to. Applications include liquid metal cooling systems for high-performance electronics, vacuum sealing for laboratory glassware and instrumentation, low-temperature casting for rapid prototyping and R&D models, and specialized heat transfer applications. Forms: approximately 2 lb cakes.
Available Forms
Approximately 2 lb Cakes
Product Code
2330
Technical Info
Thermal Properties
Melting Point (Solidus)144°F (62°C)
Melting Point (Liquidus)144°F (62°C)
Physical Properties
Density (imperial)0.285 lbs/in³
Density (metric)7.88 g/cm³
Primary ElementsIn · Bi · Sn
Lead FreeYes
Key Features
Lead-Free and Cadmium-Free144°F Eutectic Melt PointExcellent Wetting PropertiesMercury Alternative
Nominal Composition
In: 51%
Bi: 32.5%
Sn: 16.5%
Frequently Asked Questions
Common technical inquiries regarding FIELD'S Metal, 144 F, 62 C Low Melting Alloy
Field's Metal's primary advantage as a liquid metal coolant is its very low melting point of 144°F (62°C) — it remains liquid over a wide service temperature range for electronics cooling applications (60-150°C junction temperatures) and can be cycled through solid-liquid transitions without chemistry change. Its thermal conductivity (approximately 9-11 W/m·K) is higher than thermal greases and phase change materials but lower than gallium-based liquid metals (approximately 40 W/m·K for GaInSn). Field's Metal is less reactive than gallium alloys — gallium attacks aluminum and many structural alloys on contact, while Field's Metal does not, making it compatible with a wider range of heat exchanger and cold plate materials.
Field's Metal is applied to ground glass joints, flange faces, and electrical feed-throughs in vacuum systems by melting the alloy and flowing it into the joint cavity at approximately 160°F. On cooling to room temperature, the alloy solidifies to form a vacuum-tight metal seal. It seals effectively to glass, metals, and ceramics due to its excellent wetting properties from the indium content. Service temperature must remain below approximately 130°F (55°C) — below the 144°F melting point with adequate safety margin — to prevent seal relaxation under vacuum load. The seal is fully removable by gentle heating above 150°F, allowing joint disassembly and reassembly.
Field's Metal's cost is driven by the 51% indium content — indium is a rare, high-value metal primarily recovered as a byproduct of zinc smelting, with world production of only a few hundred tonnes annually and prices typically 10-50 times higher than tin per kilogram. Applications that justify the premium are those specifically requiring a lead-free, cadmium-free low melting alloy: research and development environments with strict toxicity controls, medical device prototyping, electronics liquid cooling where long-term operation near electronic components precludes lead, and educational laboratory demonstrations where student safety from cadmium and lead exposure is paramount. For applications where Wood's Metal or other cadmium/lead-bearing alloys are acceptable, those alternatives are substantially less expensive.
Bismuth-lead-tin-cadmium non-eutectic alloy (50% Bi, 25% Pb, 12.5% Sn, 12.5% Cd) with 158-169°F range for low-melting solder, metal inlays, and antique repair.
Bismuth-lead-tin non-eutectic alloy (50% Bi, 25% Pb, 25% Sn) with 203-239°F range for low-temperature soldering, heat transfer medium, and fire sprinkler valve elements.
