Crafting: how does it work?

Crafting is an in-game system allowing players to create specific items, such as a weapon, hat or materials for further crafting, using unwanted or duplicate items gained normally via the Item drop system. To create these items, the player must follow explicit blueprints, some of which are initially available and others of which must be discovered by the player by experimentation. After following a valid, undiscovered blueprint recipe, the player will both gain the item specified by the blueprint, and the blueprint will be added to the player's list of known blueprints. If the player attempts to craft an item without a corresponding blueprint, they will be notified that no such recipe exists, and no items will be lost. 

Metal

Blueprint             Requires              Produces

Smelt Primary Weapons †            2 Identical primary weapons

Eg. Force-A-Nature + Force-A-Nature    1 Scrap Metal

Smelt Secondary Weapons †      2 Identical secondary weapons

Eg. Flare gun + Flare gun               1 Scrap Metal

Smelt Melee Weapons †              2 Identical melee weapons

Eg. Übersaw + Übersaw                1 Scrap Metal

Smelt Class Weapons     Any 2 weapons wielded by the same class

Eg. Ambassador + Dead Ringer (Spy Weapons) 1 Scrap Metal

Smelt Tokens     3 Tokens

Eg. Heavy Token + Demoman Token + Melee Token       1 Reclaimed Metal

Combine Scrap Metal     3 Scrap Metal     1 Reclaimed Metal

Combine Reclaimed Metal           3 Reclaimed Metal           1 Refined Metal

Smelt Refined metal       1 Refined Metal                3 Reclaimed metal

Smelt Reclaimed metal 1 Reclaimed Metal           3 Scrap metal

    † The Smelt Class Weapons blueprint was originally one Primary, Secondary, and Melee weapon of each class, but was then altered to allow any 3 (now 2) weapons from the same class, to accommodate the Engineer, Demoman, Spy, and at the time this change was made, the Sniper. This has made the blueprints marked with a dagger superfluous.

Tokens

Blueprint             Requires              Produces

Fabricate Class Token     3 weapons from one class

Eg. Natascha + Sandvich + Sandvich (Heavy weapons)    1 Class Token

Eg. 1 Heavy Token

Fabricate Slot Token       3 weapons from one slot

Eg. Blutsauger + Huntsman + Direct hit   1 Slot Token

Eg. 1 Primary Token

Rebuild Class Token        Any one Class Token and another class's weapon

Eg. Sniper Token + Buff Banner                 1 Class Token

Eg. 1 Soldier Token

Rebuild Slot Token          Any one Slot Token and another slot weapon

Eg. Secondary Token + Axtinguisher        1 Slot Token

Eg. 1 Melee Token

    Note: If one provides 3 identical weapons, one is given the option of creating a Class Token or a Slot Token, but not both.

    Additionally, if one provides a Pain train with a Class Token, or 3 Pain trains and chooses to create a Class Token, this will always result in a Soldier Token, never a Demoman Token.

Headgear

Blueprint             Requires              Produces

Fabricate Headgear         3 Refined Metal                1 Random Headgear

Fabricate Class Headgear              4 Refined Metal + 1 Class Token                1 Class Headgear

Rebuild Headgear            2 Headgear         1 Random Headgear

Fabricate Bonk helm†    1 Batter's helmet + 2 Bonk! Atomic Punch            1 Bonk helm

    Note: As of March 19th, 2010, both hats and miscellaneous items are considered headgear.

    † The Batter's helmet's level is not retained when crafted into a Bonk helm. The level will be randomized.

Weapons

Blueprint             Requires              Produces

Fabricate Class Weapons              1 Class Token + 1 Slot Token + 1 Scrap Metal

Eg. Medic Token + Secondary Token + Scrap Metal          1 Class Specific Weapon

Eg. Kritzkrieg

Fabricate Crit-a-Cola       1 Kritzkrieg + 1 Bonk! Atomic Punch         1 Crit-a-Cola

Fabricate Dalokohs bar 1 Sandvich + 1 Bonk! Atomic Punch          1 Dalokohs bar

Fabricate Gunboats        1 Chargin' Targe + 1 Razorback   1 Gunboats

Fabricate Homewrecker               1 Eyelander + 1 Equalizer              1 Homewrecker

Fabricate Pain train         1 Sandman + 1 Scrap Metal          1 Pain train

Fabricate Scotsman's skullcutter               1 Axtinguisher + 1 Jarate               1 Scotsman's skullcutter

Fabricate Southern Hospitality   1 Ambassador + 1 Scrap Metal   1 Southern Hospitality

Fabricate Tribalman's shiv            1 Huntsman + 1 Dead Ringer       1 Tribalman's shiv

Cost summary table

Item      Total crafting cost            Smelt value

Scrap Metal        2 weapons          2 weapons

Class or Slot Token          3 weapons          2 weapons

Reclaimed Metal              6 weapons = 3 Scrap Metal or

9 weapons = 3 Tokens   6 weapons

Class-specific Weapon   8 weapons = 1 Scrap Metal + 1 Class Token + 1 Slot Token             1 weapon

Refined Metal   18 weapons = 9 Scrap Metal = 3 Reclaimed Metal              18 weapons

Random Headgear          2 headgear or

54 weapons = 27 Scrap Metal = 9 Reclaimed Metal = 3 Refined Metal      27 weapons

Class-specific Headgear                 75 weapons = (36 Scrap metal = 12 Reclaimed Metal = 4 Refined Metal) + 3 weapons (1 Class Token)       27 weapons