Blast Furnace

The Blast furnace is a late-game refining building used to process certain raw materials into metal bars using Coal as fuel. It can smelt Black Metal Scrap and Flametal Ore, making it the required processor for some of the strongest materials in Valheim. Unlike the regular Smelter, it is not used for tin, copper, iron, or silver.

A Blast furnace is unlocked after the player has killed Moder and built an Artisan Table. It must be placed within the Artisan table’s build range and can be set directly on terrain or stone structures. It cannot normally be placed on wooden structures, though this can be worked around by leveling terrain with a Hoe so the furnace sits in line with wooden floors.

In operation, the Blast furnace holds up to 20 Coal and 10 ores at a time. It consumes roughly 1 Coal every 15 seconds and takes about 30–31 seconds to produce one metal bar. The fuel and ore input ports are both on the left side of the bar output chute, which is different from the Smelter and is worth remembering when arranging a crafting area.

A few practical points make it easier to use efficiently:

• Sleeping speeds up Blast furnace processing, just like other refining structures.
• While active, it gives off the Fire effect in a radius of about 3 meters from any side, not just from the interaction point.
• Because it requires stone or terrain support, it is best placed on a stable workshop platform rather than a wooden floor unless the ground has been leveled to compensate.
• Since it only handles special ores, it is typically paired with a separate Smelter for the earlier metals and left dedicated to Black Metal scrap and Flametal ore.

Overall, the Blast furnace is the advanced metal-processing station that bridges late-game ore acquisition and high-tier equipment crafting. Its high capacity and fast production rate make it a central part of any endgame smelting setup.