The hardest metal known to man is tungsten. It has the highest tensile strength among all metals and is renowned for its ability to withstand high temperatures without melting. Tungsten is often used in applications that require extreme durability, such as in the manufacturing of light bulb filaments, cutting tools, and radiation shields. Its hardness and resistance to wear make it an essential material in various industrial fields. Additionally, tungsten's properties make it a popular choice for jewelry, particularly in wedding bands, where durability is important.