You can melt items at a smelter, using the furnace operator labor, to recover some of the metal they were made of. Decorations in a different metal are not recovered or considered; the metal recovered is the specific metal that basic item was listed as being made from. The % return is predictable and consistent for each item type, and ranges from 10%-150%, depending on the item. Higher skill levels in furnace operator speed up the process, but have no effect on the % return.
Items that yield more than 100% can be used to increase the amount of a metal you have available by producing those items and then melting them down again as many times as required. This is generally considered to be an exploit of an error in the game mechanics.
Recovered metal is measured in 1/10th's, and 1/10ths of bars of each metal are saved at the smelter where the item was melted. Fractional bars are not "shared" between smelters, nor do they exist as usable objects as is. When 10/10ths of a type of metal are accumulated at the same smelter, 1 bar of that metal is produced. If the smelter is torn down or destroyed, all fractions are lost.
- Example: If two items of the same metal worth .4 bars each are melted at the same smelter, that smelter has .8 bars worth waiting in it.
- If a similar item of a different metal is then melted there, that smelter would have .8 bars of the first metal and .4 bars of the second.
- If a similar item of the first metal is then melted at a different smelter, that smelter will have .4 of that metal, and have no connection to the fractions in the first smelter.
- If (finally!), a 3rd, similar item of the first metal is melted at the first smelter, adding another 4/10ths, and giving a total of 12/10ths of that type of metal, 1 bar of that metal is produced, and 2/10th's are waiting (plus the 4/10 of the second metal, also waiting).
So, it makes sense to designate one smelter as "melting" smelter (or for one metal type), to guarantee that fractions will add up effectively.
 Designating items to melt
You can designate metal items for melting from any interface that allows you to view the object's description screen, such as from the Stocks page or the Loo interface.
To bring up an individual object description screen when the object is:
- On the ground: Type , scroll to the object, select it from the list, and type .
- In a workshop: Type , highlight the workshop, select the object from the list, and type .
- Held by a dwarf: Type , highlight the dwarf, type to show his inventory, select the object from the list, and type .
- Inside another object: Display the container's object description screen, navigate to the specific object you wish to see, and type .
- In the stocks menu: Type Bookkeeper for how to get this), scroll to the specific object, and type to view. , hit right-direction a few times to select "stocks" and press return. Scroll to the type of object you wish to melt, type to show individual items (You have to have an exact number or this won't work. See
To designate the item, simply type forbidden then the item will not be melted.to mark the object for melting. If the item is designated for melting and
However, this only marks which items you want to be melted - you still have to place the job-order in a smelter...
 Melting the items
Items designated to be melted will be left alone until you queue a "Melt a metal object" job Smelter. Melting down an object requires the Furnace operator labor (and consumes a unit of fuel for a non-magma smelter).at a
The job gives the same experience to the furnace operator skill regardless of % yield of the item melted.
Testing is incomplete, but preliminary results show a yield of 0.3 bars times the object's material size for anything that has a material size, or 1 bar for most furniture (regardless of size).
Note that the Efficiency column is only accurate for ordinary metals - when using adamantine, the number of wafers required comes from the "Material size" column instead of "Bars to make", so if that number is larger, the efficiency will be reduced accordingly.
|Item||Material size||Bars to make||Bars returned||Efficiency|
|Weapons (made by Weaponsmith)|
|Ammo (stack of 25)||(1)||1||0.3Verify||30%|
|Siege Equipment (Weaponsmith)|
|Ballista arrow head||(4)||3||0.5Verify||17%|
|Trap Components (Weaponsmith)|
|Giant Axe Blade||5||1||1.5||150%|
|Large Serrated Disc||4||1||1.2Verify||120%|
|Trap Components (Mechanic)|
|Other objects (Metalcrafter)|
|Amulet||(1/3 to 1)||1/3 to 1||0.1Verify||10% to 30%|
|Bracelet||(1/3 to 1)||1/3 to 1||0.1Verify||10% to 30%|
|Coins (stack of 500)||(1)||1||1.1||110%|
|Crown||(1/3 to 1)||1/3 to 1||0.1Verify||10% to 30%|
|Earring||(1/3 to 1)||1/3 to 1||0.1Verify||10% to 30%|
|Figurine||(1/3 to 1)||1/3 to 1||0.2||20% to 60%|
|Ring||(1/3 to 1)||1/3 to 1||0.1||10% to 30%|
|Scepter||(1/3 to 1)||1/3 to 1||0.2Verify||20% to 60%|
All melting yields for items not specified in the raws (weapons, armor, tools, etc.) are hardcoded.