Tungsten throat reinforced with tungsten foam Tungsten is the material of choice when solid rocket propellant flame temperatures exceed the melting point of rhenium. Because tungsten can be used to coat a lighter weight material such as graphite or carbon/carbon, the cost and weight of a monolithic tungsten throat are avoided. With its proficiency in chemical vapor deposition, Ultramet can manufacture tungsten throats as coated parts or freestanding inserts.stefano grossi