Tungsten rings are composed of a metal alloy, tungsten carbide. The alloy allows for maximum hardness and rigidity without sacrificing tensile strength. Each tungsten carbide ring is cut and polished with diamond tools. Tungsten rings are not sizable by ordinary jewelers' tools -- the metal is too hard. Most tungsten metal powder is converted to tungsten carbide (WC) by reaction with pure carbon powder, e.g. carbon black, at 900 - 2200°C in pusher or batch furnaces, a process called carburisation. Tungsten is extremely hard and dense. Combined with carbon and other elements, it becomes tungsten carbide, which registers between 8-9 on the Mohs hardness scale. It’s roughly 10 times harder than 18k gold and four times harder than titanium. In addition to its design and high polish, part of its attraction to consumers is its technical nature。 Hardness, assuring long lasting beauty. Permanently polished Tungsten rings take a brilliant high polish and resist scratching longer than any metal ever offered to the public. Tungsten rings will never bend out of shape Currency: Unit Price: Quantity: Delivery: