The Ultimate Steel is a synthesized item in Atelier Meruru: The Apprentice of Arland. Ultimate Steel serves a few important purposes in development. It is a key item in creating Land Clasps which are required for development in Quelei Forest. During the enhancements done to Hart Outpost after Year 4, Ultimate Steel will be required during the Enhance Outpost II development quest. They are difficult to make, requiring high level alchemy ingredients like the Gold Nugget and Liquid Solvent. They are also required to make the highest level attack item, Peacemakers.