|This article is about the current version of DF.|
You can melt metal items at a smelter using the furnace operator labor, to recover some of the metal they were made of. Decorations of 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 percentile return is fixed and known for each item type, and ranges from 10%-150% (or more), depending on the item. Higher skill levels in furnace operator speed up the process, but have no effect on the percentile return.
Recovered metal is measured in tenths (0.1) of a full bar, and those tenths of a bar of each separate 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 ten-tenths 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.
- If 2 items, worth .4 bars each, of the same metal are melted at the same smelter, that smelter now has .8 bars (2 x .4) of that specific metal waiting in it. Not enough to use - yet...
- If a similar item of a different metal is then melted there, that smelter would still have .8 bars of the first metal, and .4 bars of the second metal.
- If a similar item of the first metal is then melted at a different smelter, that other 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, that adds another .4 bars to the .8 waiting there. This gives a total of 1.2 bars of that type of metal, meaning 1 bar of that metal is produced, ready for forging or other use, and .2 of a bar is waiting (plus the .4 of the second metal, also waiting).
It makes sense to designate one smelter as a "melting" smelter (or for one metal type), to guarantee that fractions will add up effectively. This becomes less important as you accumulate more bars of a particular metal.
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 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 hit .
- In a workshop: Type , highlight the workshop, select the object from the list, and hit .
- Held by a dwarf: Type , highlight the dwarf, type to show his inventory, select the object from the list, and hit .
- Inside another object: Display the container's object description screen, navigate to the specific object you wish to see, and hit .
- In the stocks menu: Type , hit right-direction a few times to select "stocks" and press return. Scroll to the type of object you wish to melt, hit to show individual items (You have to have an exact number or this won't work. See Bookkeeper for how to get this), scroll to the specific object, and type to view.
To designate the item, simply type to mark the object for melting. If the item is designated for melting and forbidden then the item will not be melted.
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 at a Smelter. Melting down an object requires the Furnace operator labor (and consumes a unit of fuel for a non-magma smelter).
The job gives the same experience to the furnace operator skill regardless of % yield of the item melted.
If there are items in a container that you are melting, the items will be placed inside the smelter when the container is destroyed.
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. For coins however, the number is accurate for adamantine, which only requires 1 wafers and returns 1.1 wafers when melted.
Note also that some items are always produced in twos (gauntlets, boots) or threes (flasks, goblets), or (in the case of ammo) stacks of 25 at a time, or (for coins) 500 at a time. In the case of crafts, from 1 to 3 are produced. These are shown as "1/x" below, although a single job will never use less than one bar, nor produce less than the pair/trio/etc. of items.
|Item||Material size||Bars to make||Bars returned||Efficiency|
|Weapons (made by Weaponsmith)|
|Ammo (full stack of 25)||(1)||1||0.3||30%|
|Ammo (single bolt)||(1)||1/25||0.1||250%|
|Trap Components (Weaponsmith)|
|Giant Axe Blade||5||1||1.5||150%|
|Large Serrated Disc||4||1||1.2||120%|
|Trap Components (Mechanic)|
|Siege Equipment (Weaponsmith)|
|Ballista arrow head||(4)||3||0.5||17%|
|Furniture (Blacksmith / Metalsmith)|
|Other objects (Metalcrafter)|
|Amulet||(1/3 to 1)||1/3 to 1||0.1||10% to 30%|
|Bracelet||(1/3 to 1)||1/3 to 1||0.1||10% to 30%|
|Coins (stack of 500)||(1)||1||1.1||110%|
|Coins (stack of 1)||(1)||1/500||0.1||5000%|
|Crown||(1/3 to 1)||1/3 to 1||0.1||10% to 30%|
|Earring||(1/3 to 1)||1/3 to 1||0.1||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||0.2||20% to 60%|
All melting yields for items not specified in the raws (weapons, armor, tools, etc.) are hardcoded.
Metal bars are able to be melted and remade into half a bar at a smelter. (Melt 1 tin bar, return as 0.5 tin bar + experience.)
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. However, using a dwarf with a high skill level to make the items will result in severe tantrums being thrown when all the ☼masterwork☼ creations start being melted, so you will need to utilize low-skill metalworkers and make sure their skill levels don't get too high to avoid masterwork items, or you will have tantrum spirals, fistfights, and/or lots of
useless junk valuable trade goods lying around. (A workshop profile on the forge can be used to restrict production to dwarves below a certain skill level.)