Tungsten is used in furnaces for several reasons:

1. High melting point: Tungsten has an extremely high melting point of 3,422 degrees Celsius (6,192 degrees Fahrenheit), one of the highest melting points of all metals. This makes tungsten an ideal material for furnace components that are subject to extremely high temperatures, such as heating elements and crucibles.

2. Thermal stability: Tungsten exhibits excellent thermal stability even at high temperatures. This property allows tungsten components to withstand the high temperatures generated within furnaces without deformation or degradation, ensuring long-term reliability and performance.

3. Thermal conductivity: Tungsten has high thermal conductivity and can achieve efficient heat transfer in the furnace. This property contributes to uniform heating and temperature distribution, which is critical for various high-temperature processes such as metal melting, sintering and heat treatment.

4. Corrosion resistance: Tungsten is highly resistant to chemical attack and oxidation at high temperatures, making it suitable for use in aggressive furnace environments where other materials may degrade or react with the surrounding atmosphere.

Overall, tungsten’s high melting point, thermal stability, thermal conductivity, and corrosion resistance make it an excellent choice for furnace components, especially in applications involving extreme heat and harsh operating conditions.