Certain upgrade materials in NieR: Automata are notoriously difficult to acquire. While many drop from enemies, some, like Filler Metal, are randomly found in the environment. This inherent randomness makes farming these items challenging.
This guide details two methods for obtaining Filler Metal: finding it in the game world and purchasing it.
Filler Metal is a rare item found in specific locations within the Factory area. The exact spawn points are randomized each time you enter the Factory, making consistent farming unreliable. Filler Metal has a low spawn rate compared to other items.
The Factory: Hanger access point provides the most efficient starting point for searching. However, you may need to progress through the main story to unlock or re-unlock this access point.
While movement speed boosts can slightly improve your chances, reliably farming Filler Metal remains difficult. The most effective strategy is to thoroughly explore the Factory, collecting every item you encounter. However, purchasing it is ultimately a more reliable method, especially later in the game.
The only vendor selling Filler Metal is the Shopkeeper Machine in the Amusement Park. However, this option only becomes available after completing all three playthroughs and obtaining one of the final endings. Using Chapter Select to revisit the Shopkeeper after completing the game will allow you to purchase Filler Metal for 11,250 G each.
This high price is offset by the guaranteed acquisition, making it a far more reliable method than random farming in the Factory. Considering the necessity of Filler Metal for Pod upgrades to overcome high-level enemies, purchasing it is often the more practical approach.