Hinge is a joint. It is designed to join two 'arms' together while letting them move freely. A lever is when a pivot, load, effort is present. Although hinge itself is not a lever, but taking our biceps as an example, that would be a Class 3 lever.
Physical properties. Tungsten is a hard brittle solid whose color ranges from steel-gray to nearly white. Its melting point is the highest of any metal, 3,410Â°C (6,170Â°F) and its boiling point is about 5,900Â°C (10,600Â°F). Its density is about 19.3 grams per cubic centimeter. Tungsten conducts electrical current very well.
Why is tungsten carbide the most scratch resistant metal known to man? Tungsten molecules arrange themselves like a 3D version of a chain linked fence, which gives it extreme hardness. It is so tough, it is sometimes classified as a ceramic, which is known for its ability to withstand high temperatures and resist wear.