Stone furnace

The Stone furnace is a basic smelting building in Factorio used to convert ore into plates or to produce stone bricks and steel when supplied with the appropriate input. When fueled with coal, the Stone furnace consumes coal at a rate of 0.0225 coal per second while producing items at fixed output rates depending on the recipe.

The production rates for common recipes when the Stone furnace is actively smelting are:

• Iron plate: 0.3125 iron plates per second.
• Copper plate: 0.3125 copper plates per second.
• Stone brick: 0.3125 stone bricks per second.
• Steel plate: 0.0625 steel plates per second.

Compared to more advanced furnaces, the Stone furnace produces plates at half the speed of a Steel furnace or an Electric furnace for iron, copper, and stone brick (0.3125 vs 0.625 items/sec). The steel plate output is likewise half that of a Steel or Electric furnace (0.0625 vs 0.125 steel plates/sec). The coal consumption of 0.0225 coal/sec corresponds to the fuel cost while smelting; efficiency and energy source differ for other furnace types.

Practical notes and considerations:

• The Stone furnace is suitable for early-game smelting and small-scale setups due to its low resource and technology requirements.
• Use Stone furnaces for early-production of iron and copper plates until you can research and build Steel furnaces or Electric furnaces for higher throughput.
• Steel production in Stone furnaces is available but very slow; upgrading to Steel or Electric furnaces doubles steel output.
• Arrange Stone furnaces with inserters and belts to ensure a steady supply of ore and fuel and to fully utilize their modest production rates.
• Replace Stone furnaces with higher-tier furnaces as soon as throughput demands or resource efficiency require it.