General
Guide to Smelting and Furnaces in Rust
Every furnace type, how smelting works, charcoal management, and how to run your resource production efficiently.
Every furnace type, how smelting works, charcoal management, and how to run your resource production efficiently.
Every piece of refined metal, sulfur, and high-quality metal in Rust starts as raw ore that requires smelting. Furnaces are the backbone of your resource production system. Understanding furnace types, smelting ratios, and charcoal management determines how quickly you progress from early game to endgame.
Small Furnace - The entry-level furnace costing 200 stone, 100 wood, and 50 low-grade fuel. It has three smelting slots and processes ore slowly. Early wipe, you should build 2-3 small furnaces in parallel to compensate for speed. Small furnaces are cheap and useful for bootstrapping, but become obsolete once you progress.
Large Furnace - Costs 1,500 stone and significant wood. It smelts much faster than small furnaces and handles the workload of several small ones simultaneously. One large furnace replaces 4-5 small furnaces. Large furnaces require more floor space and are vulnerable if placed outside or in accessible areas. Protect them during raids.
Electric Furnace - Runs entirely on electricity instead of wood fuel. It is faster than large furnaces with no charcoal byproduct. The best option if you have power infrastructure. Requires significant power generation but eliminates fuel consumption. No charcoal means you need another source for gunpowder production.
Metal Ore to Metal Fragments - The most common smelt. Metal ore converts to metal fragments at a 1:1 ratio. Metal fragments are used for tools, weapons, building upgrades, and electrical components. You will always need metal fragments.
Sulfur Ore to Sulfur - Smelts at a 1:1 ratio. Sulfur is used exclusively for gunpowder crafting, explosives, and ammunition. Gunpowder is essential for raiding and is the bottleneck resource for many players.
HQM Ore to High Quality Metal - Converts at a 1:1 ratio but smelts significantly slower than other ores. High-quality metal is used for armored parts, C4, and tier-3 items. Each HQM ore takes substantial time to process.
Charcoal Production - Wood burned as fuel in furnaces produces charcoal as a byproduct. Each wood burned produces one charcoal as a byproduct. Keep all charcoal you produce; it is vital for gunpowder crafting.
Small furnaces smelt one ore at a time using wood as fuel plus additional fuel to keep furnaces running. Large furnaces are more fuel-efficient per ore processed. Electric furnaces eliminate fuel costs entirely but require power infrastructure. Calculate fuel needs before starting large smelt operations to avoid running out mid-process.
Wood is the only furnace fuel. Place wood and ore together in a furnace. The furnace burns wood and produces charcoal as a byproduct. Keep all charcoal for gunpowder crafting.
Charcoal builds up quickly when running multiple furnaces. Do not discard it. Charcoal combined with sulfur makes gunpowder, which is the foundation of all raiding and most ammo crafting. Store charcoal in containers at your base. If you run electric furnaces exclusively, you produce zero charcoal. Keep at least one wood-burning furnace running on the side to generate charcoal stockpiles, or preserve charcoal from earlier wipe phases.
A healthy charcoal stockpile of 2,000+ units ensures you never run short for gunpowder production. Without charcoal, you cannot craft explosives or ammunition efficiently.
The Oil Refinery converts crude oil into low-grade fuel at a 3:1 ratio. Each crude oil produces 3 low-grade fuel. Refineries require a 1x1 space and simple input/output setup. Put crude oil and wood inside, turn it on, and let it process. If you use vehicles, explosives, or furnaces regularly, an oil refinery at base is worth the investment. It creates fuel independence and enables sustained operations.
There is no reason to sit on unsmelted ore. Load your furnaces whenever you have ore and let them run continuously. The sooner ore is smelted, the sooner you can use the materials or trade them. Unused ore is wasted potential.
Build furnaces near your resource storage and tool cupboard. Minimize carry distance for ore and fuel. Place furnaces in protected rooms or behind walls to prevent theft. Multiple furnaces running in parallel speed production significantly. A setup with 4-5 large furnaces or 1 electric furnace handles mid-wipe resource needs efficiently.
Check furnaces regularly. Full output slots pause processing. Empty output slots constantly to prevent bottlenecks. A furnace waiting for you to pick up refined metal is inefficient. Schedule regular collections to maintain maximum processing throughput.
For resource farming strategies see the Farming guide. For crafting requirements see the Crafting guide. For gunpowder production see the Gunpowder guide.