Foundry

The Foundry is a late-game crafting building introduced for use on Vulcanus, where it serves as the main machine for molten-metal processing and specialized casting. It has a built-in +50% productivity bonus and high crafting speed, making it one of the most efficient production buildings in the game for a wide range of metal-related recipes.

Unlike ordinary furnaces or assembling machines, the Foundry can both create molten iron and molten copper from ore and calcite, and then use those molten metals to cast finished products. It also has a unique crafting recipe of its own, along with several Vulcanus-only recipes such as molten-metal production, the metallurgic science pack, the big mining drill, and the Turbo transport belt family. One recipe must be selected before the building can begin working.

Most of the Foundry's recipes are more resource-efficient than doing the same work in a furnace or assembler, and the built-in productivity bonus applies even to recipes that would not normally benefit from productivity modules, such as belt production. This means its real output is often better than the base recipe numbers suggest. For example, 200 iron ore processed into molten iron in an unmoduled Foundry can be turned into 3,000 molten iron, enough for 450 iron plates.

The Foundry is especially strong for casting basic metal intermediates and finished goods:

• It can cast iron plates, steel plates, copper plates, iron gear wheels, iron sticks, pipes, pipe to ground, copper cable, and low density structures.
• Concrete has a special Foundry recipe that can benefit from productivity modules, unlike the regular concrete recipe.
• It can also cast tungsten plate from tungsten ore and molten iron, and holmium plate from holmium solution.
• On Vulcanus, it is also used for making advanced items such as the big mining drill, the metallurgic science pack, and the Foundry itself.

There are also alternative production chains that can be more efficient than casting final products directly. For example, plates can be cast in the Foundry and then turned into steel, gears, sticks, pipes, copper cable, or low density structures in another machine. These chains often require more buildings and more setup, but they can outperform direct casting depending on module quality and research bonuses. In particular, steel production can become extremely competitive when combined with infinite productivity research, and the best choice depends on the desired output rate and available module tiers.