Furnace 13

Lore & Background

In the Factorio world, the player arrives on a desolate, alien planet and must bootstrap an industrial civilization from nothing. The furnace is, in many ways, the first true act of creation: a pile of iron ore and a lump of coal become a flat, useful plate. The Stone Furnace is rough, hand-built, and slow—its stone walls radiate a dull orange glow that speaks of early, fragile ambition. Upgrading to the Steel Furnace is the first moment the base feels *industrial*, its metal casing swallowing the heat and doubling throughput. The Electric Furnace completes the triad. It no longer chews coal; it drinks from the power grid, humming with a steady blue-white light. For fans, the progression from stone to steel to electric mirrors the broader narrative arc of the game: from solitary survival to sprawling, interlocking automation. The 'Furnace 13' label, while not official, captures the feeling that these three machines are the beating heart of the entire tech tree—remove them and nothing else can be built. In the game's quiet, mechanical storytelling, the furnaces never speak. They simply convert. Ore in, plates out. But to the player watching a factory grow from a single smelter to a wall of electric furnaces, that conversion feels almost sacred.

In Their Own Story

The wind off the salt flats carried a thin taste of sulfur. Mara knelt beside the Stone Furnace, pressing her palm against its rough face. The coal was low; the iron ore pile was half-eaten. She fed it another chunk, watched the interior glow shift from dull amber to a brighter, more honest orange. Somewhere behind her, the first conveyor belt clattered to life, carrying copper ore toward a second furnace she hadn't even named yet. She thought about the Steel Furnace she'd sketched on a scrap of paper in the early hours—four times the speed, a clean metal shell, no more shoveling coal by hand. And beyond that, the Electric Furnace, which would need a generator, which would need a turbine, which would need a whole grid of pipes and wires she couldn't yet imagine. But tonight, one stone furnace and one glowing ingot were enough. She patted the warm wall, stood up, and walked back toward the base. The factory was small. It was hers. And it was already hungry for more.

Reader's Guide

The furnace progression in Factorio is the earliest and most critical production chain. The Stone Furnace is available from the start (no research required) and smelts iron ore, copper ore, and, with two iron ore inputs, steel. It burns coal as fuel. The Steel Furnace is unlocked via the 'Steel Furnace' technology in the Production tab. It requires Steel as a prerequisite resource, meaning you must first smelt iron ore and then smelt iron ore again (two-to-one) to produce steel. This creates a natural pacing gate: you cannot skip ahead. The Steel Furnace doubles smelting speed and fuel capacity. The Electric Furnace is unlocked via the 'Electric Furnace' technology, which requires the 'Electric Engine' or equivalent power-tech prerequisites. It replaces coal with electricity (0.5 kJ per smelting cycle), freeing up coal for other uses and enabling cleaner, more scalable production. It requires a power grid—generators, turbines, or solar arrays. In blueprint terms, the furnace is the foundational building block of nearly every blueprint a player shares. Community 'blueprint books' almost always begin with a smelting layer. Because furnaces are the first production machines, blueprint designs that ignore furnace spacing or fuel routing tend to collapse under load. The tech-tree interaction is straightforward: you cannot research Steel without smelting, and you cannot smelt steel without a furnace. The entire tree is, in a very literal sense, built on top of the furnace.

Did You Know?

• The Stone Furnace is the only production machine in Factorio that requires zero research to place—every player's first factory starts with it.
• Smelting steel requires two iron ore as input for one steel output, making it the only '2-to-1' smelting recipe in the base game.
• In the game's internal data, all three furnace types share the same base entity structure; the differences are in fuel type, speed multiplier, and energy consumption, which is why they can be swapped in place during upgr