Furnace 17

Lore & Background

In the Factorio community, furnace tiers have become a kind of litmus test for a player's industrial maturity. The Stone Furnace is the first taste of smelting—clunky, slow, but transformative. By the time a player is stacking Electric Furnaces into multi-layered smelting farms, the game has already shifted its focus toward logistics, energy, and the alien threat. The Advanced Furnace, introduced in the 2.0 update, added a new speed tier and a new fuel/energy interplay, and even that felt like the natural capstone. 'Furnace 17' lives in the gap after that capstone. It is the number a player mutters when they stare at a wall of Advanced Furnaces and think, *there has to be more.* The specific number—seventeen—carries no in-game meaning; it is simply a large enough digit to feel absurd, to signal that the smelting process has been iterated so many times it has become almost ritualistic. In fan art and forum jokes, Furnace 17 is depicted as a sleek, almost organic structure that no longer needs fuel or electricity so much as it simply *converts raw ore into refined metal through sheer industrial will.*

It is, in the end, a love letter to the game's core loop: take rock, make it into something better, and keep going. The number seventeen is arbitrary, but the feeling behind it is very real to anyone who has ever watched a conveyor belt of iron plates flow endlessly into a furnace and thought, *I could do this forever.*

In Their Own Story

The night shift at the outer smelting yard was quiet in the way that only a fully automated factory can be quiet—not silent, never silent, but a low, rhythmic hum of pistons and the soft clink of plates dropping into hoppers. Mara wiped her hands on her coveralls and leaned against the rail of the catwalk, watching the orange glow of the last Advanced Furnace pulse in the dark. Below her, the belt fed iron ore into the intake with a steady, almost meditative rhythm. *Clink, clink, clink.* Each plate that emerged was a little brighter, a little purer than the rock that had gone in. She'd been running this line for three days straight, and the numbers on her tablet kept climbing—throughput, efficiency, yield. The game's little progress bar had long since filled, and yet the furnace kept going, as if it didn't know or care that its purpose had been fulfilled. She pulled out her stylus and, on the back of a discarded blueprint sheet, sketched a new design. No fuel input. No electricity port. Just a smooth, dark housing with a single glowing seam where the ore went in and the plate came out. She labeled it, with a small grin, *Furnace 17.*

It would never be researched. It would never be built. But the sketch sat in her pocket for the rest of the night, and the hum of the real furnaces below felt, just for a moment, like a promise that there was always one more tier waiting.

Reader's Guide

Furnace 17 does not exist in the official Factorio technology tree, so there is no research cost, prerequisite chain, or unlock condition to describe. What does exist is the canonical furnace progression that the community concept builds upon. The furnace line begins with the Stone Furnace, available from the start, which smelts iron and copper ore using coal or wood. The Steel Furnace (researched in the Steel Processing tech group) doubles smelting speed and accepts more fuel types. The Electric Furnace (Electric Power tech) removes fuel entirely, drawing energy directly from the grid and further increasing throughput. The Advanced Furnace, added in the 2.0 update, sits at the top of the chain, offering the highest smelting rate and a new interaction with the energy system. In the community, 'Furnace 17' is sometimes used as shorthand for the hypothetical next tier beyond Advanced. Players joke about it in the context of blueprint sharing: a save file containing a 'Furnace 17' layout would be a purely decorative or aspirational build, since the item cannot be placed. It also appears in fan-made mod discussions, where mod authors occasionally create speculative furnace tiers for fun, but none of these are part of the base game. If you are looking for the actual endgame smelting setup in vanilla Factorio, the Advanced Furnace is your final furnace. Pair it with efficient power generation and well-planned logistics, and the smelting bottleneck effectively disappears for the rest of your campaign.

Did You Know?

• The Advanced Furnace was the first new furnace tier added since the game's early access period, arriving with the 2.0 update in 2023, which made the 'next furnace' a hot topic in the community.
• In Factorio, furnace smelting speed scales with the furnace tier, but the *recipe* for the smelted product remains identical—meaning a Stone Furnace and an Advanced Furnace produce the exact same iron plate, just at very
• The game's blueprint and save-sharing system works by encoding build layouts into a shareable string or file, so a fan-made 'Furnace 17' layout could theoretically be shared as a decorative build even though the item its
• Factorio's furnace icons in the item list have a small visual progression—stone texture, brushed steel, a sleek electric housing, and the Advanced Furnace's more refined silhouette—making the 'missing next tier' easy to