Galinstan (R) is a brand name for a alloy composed of gallium, indium, and tin which melts at and is thus liquid at room temperature. However, it is not a eutectic alloy but a near eutectic alloy. In scientific literature, galinstan is also used as an acronym denoting the eutectic composition of the alloy of Ga-In-Sn, which melts at around . The composition of both alloys is roughly the same, albeit the Galinstan (R), the technical product of a company, has likely additions of flux to improve flowability, reduce melting temperature, and reduce surface tension. The physical properties of the Galinstan (R) and the pure eutectic alloy EGaInSn thus differ slightly. Galinstan is composed of 68.5%Ga, 21.5%In, and 10.0%Sn (by weight). Due to the low toxicity and low reactivity of its component metals, in many applications, galinstan has replaced the toxic liquid mercury or the reactive NaK (sodium–potassium alloy). Name The name "Galinstan" is a portmanteau of gallium, indium, and stannum (Latin for "tin"). The brand name "Galinstan" is a registered trademark of the German company . Physical properties Boiling point: >1300°C Vapour pressure: <10−8Torr (at 500°C) Solubility: Insoluble in water or organic solvents Viscosity: 0.0024Pa·s (at 20°C) Thermal conductivity: 16.5W·m−1·K−1 Electrical conductivity: 3.46×106 S/m (at 20°C) Surface tension: s = 0.535–0.718 N/m (at 20°C, dependent on producer) Unlike mercury, galinstan tends to wet and adheres to many materials, including glass, which can limit its use as a direct replacement material in some situations. Uses The non-toxic galinstan replaces mercury in thermometers; the tube interior must be coated with gallium oxide to prevent it from wetting the glass. Galinstan has higher reflectivity and lower density than mercury. In astronomy, it can replace mercury in liquid-mirror telescopes. Metals or alloys like galinstan that are liquids at room temperature are often used by overclockers and enthusiasts as a thermal interface for computer hardware cooling, where their higher thermal conductivity compared to thermal pastes, and thermal epoxies can allow slightly higher clock speeds and CPU processing power achieved in demonstrations and competitive overclocking. Two examples are Thermal Grizzly Conductonaut and Coolaboratory Liquid Ultra, with thermal conductivities of 73 and 38.4 W/mK respectively. Unlike ordinary thermal compounds which are easy to apply and present a low risk of damaging hardware, galinstan is electrically conductive and causes liquid metal embrittlement in many metals including aluminum which is commonly used in heatsinks. Despite these challenges the