They are used in the Construction skill to make certain furniture, and can also also be hammered onto flighted ogre arrows to create mithril brutal arrows, requiring 49 Fletching and granting 7.5 experience. They can also be obtained during the quest In Aid of the Myreque. Mithril nails are tradeable, durable, and quite cheap as well, making them an excellent choice for lower-level furniture that uses nails. 90 mithril nails are required for the quest Catapult Construction.