Men's and Women's Tungsten Carbide Wedding Band Ring with Blue Carbon Fiber Inlay (Available Sizes 7-15.5) 8mm Tungsten Carbide is the only rare and exotic metal that has a permanent polish and finish that will endure until the end of time. The heavy weight and the enduring finish of a tungsten carbide ring, speak of commitment, security and an everlasting bond. Tungsten Rings are the most wear-resistant rings available on the planet. Each Tungsten ring is individually hand-crafted using assorted diamond abrasives and polycrystalline diamond tooling. All of our rings are comfort fit . The inside edges are perfectly shaped for maximum comfort.