In Smithing it is used for the process of smelting, that is separating out impurities in ores from the metal to make metal bars. Smelting different ores requires different Smithing levels. It may also require more than one type of ore, and varying amounts of coal in some cases.
Players with Level 43 Magic may choose to use Superheat Item instead of furnaces for smelting, earning both Magic and Smithing experience, although this will prove costly as it requires 1 nature rune per bar (if you have a Staff of fire equipped). Superheat Item does not work for jewellery.
A furnace is also needed for some Crafting purposes. With the appropriate mould and Crafting level required, players can use the furnace to craft gold bars into jewellery (e.g. rings, necklaces, bracelets, amulets) with or without gems. Players can also craft silver bars into holy symbols, tiaras, unholy symbols, or lightning rods depending on their Crafting level and the mould they have in their inventory. Players may also make molten glass by smelting soda ash and a bucket of sand.
|Al-Kharid||This furnace is located just a little north of the bank. It is very close to a bank and is excellent for players with many ores in their bank. This is the recommended furnace for players who cannot access the ones in Port Phasmatys, Neitiznot, or Edgeville. This furnace is also the closest furnace to a bank in f2p|
|Falador||This furnace is located south of the centre. It is very close to both the east bank and the west bank. This is also a recommended furnace, though Al-Kharid's furnace is slightly closer to a bank.|
|Lumbridge||This furnace is located north of Lumbridge castle. The next closest bank is in Lumbridge Castle.|
|Wilderness, Level 28||Located in the Wilderness at level 28, it is only useful for the mines in the Wilderness. However, players can also be killed by revenants while using this furnace.|
|East Ardougne||This furnace is very close to a bank and is great if a player has many ores in their bank.|
|Burgh de Rott||This furnace is not a good place to smelt as there are no significant mining areas nearby (except maybe for the Abandoned Mine), and the bank is not accessible until you repair it as part of the In Aid of the Myreque quest. It is useful for smithing quest related items and ores received from Temple Trekking.|
|Edgeville||New furnace available after completing tasks of Varrock Diary and wearing the Varrock armour. Chance of smelting 2 bars at once for faster experience and very close, just east of bank. Contrary to what some people think, the removal of the door does not mean that it can now be used without completing the achievement diary tasks.|
|Enakhra's Temple||Requires Enakhra's Lament quest. Very far from a bank. Sometimes used for smelting gold from the nearby gold mine south-west of Nardah.|
|Entrana||This furnace is mainly used in Crafting to make glass as all the materials are on the island. The closest bank, Draynor is far away.|
|Dorgesh-Kaan||Death to the Dorgeshuun required. is very close to an anvil, but far from a bank.|
|Keldagrim||The Giant Dwarf quest is needed to have been started or completed to enter the city. The furnace is actually Blast Furnace minigame. 2500 coins (1250 coins with a Ring of charos) are needed to use it if your smithing is lower than level 60. The upside is it uses half as much coal to make high level metal bars, and there is a nearby NPC selling ores for you.|
|Meiyerditch||The Legacy of Seergaze quest must be completed up to a certain point. Extremely far from both a bank or a mine, its use is mainly to create items for the quest.|
|Neitiznot||The second closest furnace to a bank in all RuneScape. The Fremennik Trials quest is required. Named clay forge. However, the bank does not have a Collection Box if you are awaiting any offers from the Grand Exchange.|
|Piscatoris||Quite close to a bank. Swan Song is required. A very nice furnace because there's nobody usually smelting here, and you can take short breaks to fish.|
|Port Phasmatys||This furnace is the closest furnace to a bank in RuneScape. Wearing a Ghostspeak amulet speeds up banking but is not required.|
|Rellekka||Usable after completing the quest The Fremennik Trials. A bank is a long walk away, but this furnace is the closest to an anvil in all of RuneScape.|
|Shilo Village||The Shilo Village quest is required to enter the village. Very close to a bank but players must pay 20 coins every time they want to use it.|
|Tyras Camp||Requires Regicide quest to be started. A really long walk away from a bank.|
|TzHaar city||Is actually a lava forge but has the same options as furnace. Bank is near, close by the gold mine.|
|Zanaris||The Lost City quest has to be completed to enter this fairy city.|