Valheim's Metal Chain: Charcoal Kiln, Smelter and Blast Furnace
The Blast Furnace is not faster than the Smelter. It burns coal at the same rate, produces a bar in the same 30 seconds, and holds the same amount of both. The only thing that separates them is what each one will accept — and that single difference is what gates Black Metal and Flametal behind Moder. Here is the whole metal chain, with the numbers that decide how often you have to go and refill it.
On sourcing. Iron Gate do not publish system documentation. The figures below come from the community wikis and can change with any patch.
The Three Buildings
| Building | Materials |
|---|---|
| Charcoal Kiln | Stone ×20, Surtling Core ×5 |
| Smelter | Stone ×20, Surtling Core ×5 |
| Blast Furnace | Stone ×20, Surtling Core ×5, Iron ×10, Finewood ×20 |
All three need Surtling Cores, which come from Burial Chambers in the Black Forest. That is worth stating plainly, because it means the entire metal economy starts in the Black Forest — before you have any metal at all. A player who clears crypts for copper and ignores the cores will find themselves unable to smelt it.
Five cores per building, three buildings, and you will want more than one Smelter — budget twenty or more cores from your Burial Chamber runs.
The Charcoal Kiln makes the fuel the other two consume, converting Wood into Coal, and it holds 25 Wood at a time.
Identical Rates, Different Menus
| Smelter | Blast Furnace | |
|---|---|---|
| Fuel | 1 Coal per 15 s | 1 Coal per 15 s |
| Output | 30 s per bar | 30 s per bar |
| Coal capacity | 20 | 20 |
| Ore capacity | 10 | 10 |
Every number is the same. The Blast Furnace is a wider menu, not a better machine — which is useful to know before you tear down a working Smelter expecting an upgrade.
It also means you should keep both. Since the Blast Furnace has no throughput advantage, running a Smelter for copper, tin, iron and silver alongside a Blast Furnace for black metal and flametal simply doubles your output. Replacing one with the other halves it.
What Each One Smelts
| Smelter | Blast Furnace only |
|---|---|
| Copper Ore | Black Metal Scrap |
| Tin Ore | Flametal Ore |
| Silver Ore | |
| Scrap Iron | |
| Copper Scrap | |
| Iron Ore |
Two materials, and both are late-game tiers. Black Metal Scrap is the Plains weapon tier; Flametal Ore is the Ashlands armour tier at 38 – 44 armour per piece.
And the Blast Furnace requires the Artisan Table to build, which requires Dragon Tears from Moder. So the chain is: beat Moder → Artisan Table → Blast Furnace → Black Metal. You can gather Black Metal Scrap in the Plains long before you can process any of it, which catches out players who skip the Mountain.
Running the Chain Efficiently
Here is the arithmetic that makes a smelting setup low-maintenance.
A full Smelter holds 20 Coal, burning one every 15 seconds — 300 seconds of fuel. It also holds 10 ore, producing a bar every 30 seconds — 300 seconds of work.
They run out at exactly the same moment. That is not a coincidence, and it is genuinely useful: top up coal and ore in the same visit and neither will idle. A furnace that stops early is almost always one that was given ore without matching fuel.
Scale that up. Each furnace burns 1 Coal per 15 seconds, so two furnaces running together consume coal twice as fast — and a Charcoal Kiln holding 25 Wood is what has to keep up. Most bases end up with more kilns than furnaces for exactly this reason.
And mind the smoke. A Smelter indoors will stop working when smoke accumulates — see smoke and ventilation. The standard solution is a roof with a deliberate gap, or simply leaving the furnaces outdoors under an overhang.
Finally, remember what cannot be moved. Ore cannot be teleported, so your smelting site should be wherever the ore arrives by ship, not wherever your main hall happens to be. Many players build a small dockside smelting camp and portal the finished bars home — bars are teleportable, ore is not.
How to Set Up the Metal Chain
- Farm Surtling Cores in Black Forest Burial Chambers — five per building, and you want twenty or more.
- Build the Charcoal Kiln first, since both furnaces need its output.
- Keep the Smelter when you build the Blast Furnace. They are equally fast, so two is double output.
- Refill coal and ore together — 20 coal and 10 ore both last 300 seconds.
- Build more kilns than furnaces. Fuel is the bottleneck.
- Site the smelting camp at the dock, and portal the finished bars home.
Practical tips
- Smelter and Blast Furnace are identical in speed — 1 coal per 15 s, 30 s per bar, 20 coal, 10 ore.
- The Blast Furnace only adds Black Metal Scrap and Flametal Ore. Keep both buildings.
- All three buildings need Surtling Cores, so the metal chain starts in the Black Forest.
- 20 coal and 10 ore both run 300 seconds — top up together and nothing idles.
- Smoke stops a smelter indoors. Vent the roof or build outside.
- Ore cannot be teleported but bars can. Smelt at the dock, portal the output.
Running your own Valheim server
Smelting is the clearest case for a world that keeps running — a full Smelter takes five minutes to work through its load, and on a single-player save that clock stops the moment you log out. A gamever Valheim server keeps furnaces burning and kilns converting for up to 10 players, so a hold of ore hauled in on Tuesday is bars by Thursday. One-click backups protect a smelting camp built from twenty Surtling Cores, and automatic updates keep client and server aligned.
Conclusion
Valheim's metal chain is three buildings, and all of them cost Surtling Cores — which means the whole economy starts with Black Forest Burial Chambers, before you own any metal. The Charcoal Kiln (Stone ×20, Surtling Core ×5) holds 25 Wood and makes the coal the others burn. The Smelter and the Blast Furnace are identical machines: 1 coal per 15 seconds, one bar per 30 seconds, 20 coal and 10 ore capacity each. Their only difference is the menu — the Blast Furnace alone accepts Black Metal Scrap and Flametal Ore, and it requires the Artisan Table, and therefore Moder. Keep both rather than upgrading, since equal speed means two buildings are double output. And the number worth remembering: 20 coal and 10 ore both last exactly 300 seconds, so refill them together and nothing sits idle.
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