The Hardening Bucket sits on the metallurgy tab next to the anvils and runs no recipe of its own — but it is not decoration. The three anvils record it as their extension, and 17 forging recipes carry it as a requirement, Bronze Detail first among them. Here is its cost, the research behind it, and the placement that makes it work.
Build cost & research
Building
Recipes
Build cost
Where
Unlocked by
Hardening Bucket
—
Wooden Plank ×4 Bronze Nails ×8
Yard
Bronze Craft 30R
Costs and research come straight from the game data, and “Where” is the work zone whose build desk offers the building — the game’s own placement record. “No research listed” means the page has none to show: either this build records none, or the game ships no name for it. In practice these rows are gated by materials, not by the tech tree.
What this unlocks
Recipe
Ingredients
Ticks
Station
Bronze Detail ×6
Bronze Ingot ×1
5
Wooden Anvil · Iron Anvil · Steel Anvil
Iron Kit I ×1
Iron Ingot ×1
8
Iron Anvil · Steel Anvil
Bronze tools ×1
Stick ×2 Polished Bronze ×1 Bronze Detail ×4
8
Wooden Anvil · Iron Anvil · Steel Anvil
Iron tools ×1
Stick ×2 Iron Detail ×2 Advanced Detail ×2
8
Iron Anvil · Steel Anvil
Steel tools ×1
Stick ×2 Steel Detail ×2 Engineering Details ×2
8
Steel Anvil
Bronze Axe ×1
Stick ×2 Bronze Detail ×2 Bronze Ingot ×1
8
Wooden Anvil · Iron Anvil · Steel Anvil
Iron Axe ×1
Stick ×2 Iron Detail ×2 Iron Ingot ×1
8
Iron Anvil · Steel Anvil
Steel Axe ×1
Stick ×2 Steel Detail ×2 Steel Ingot ×1
8
Steel Anvil
Bronze Pickaxe ×1
Stick ×2 Bronze Detail ×2 Bronze Ingot ×1
8
Wooden Anvil · Iron Anvil · Steel Anvil
Iron Pickaxe ×1
Stick ×2 Iron Detail ×2 Iron Ingot ×1
8
Iron Anvil · Steel Anvil
Steel Pickaxe ×1
Stick ×2 Steel Detail ×2 Steel Ingot ×1
8
Steel Anvil
Bronze Hammer ×1
Stick ×2 Bronze Detail ×2 Bronze Ingot ×1
8
Wooden Anvil · Iron Anvil · Steel Anvil
Iron Hammer ×1
Stick ×2 Iron Detail ×2 Iron Ingot ×1
8
Iron Anvil · Steel Anvil
Steel Hammer ×1
Stick ×2 Steel Detail ×2 Steel Ingot ×1
8
Steel Anvil
Bronze Shovel ×1
Stick ×2 Bronze Detail ×2 Bronze Ingot ×1
8
Wooden Anvil · Iron Anvil · Steel Anvil
Iron Shovel ×1
Stick ×2 Iron Detail ×2 Iron Ingot ×1
8
Iron Anvil · Steel Anvil
Steel Shovel ×1
Stick ×2 Steel Detail ×2 Steel Ingot ×1
8
Steel Anvil
All 17 of these recipes carry this extension in the game data: they only appear at Wooden Anvil · Iron Anvil · Steel Anvil once the part stands next to it.
If the anvil will not craft: check the bucket
Place the bucket beside an anvil, not on it. While a part is being placed the game draws the area it covers, and the anvil has to be inside that area.
Re-open the anvil's crafting menu after moving the bucket — the recipes that need it only become available once it is in range (players report the entry stays greyed out until then).
Inspiration level is not the blocker: Bronze Detail needs level 2, and the anvil's first bronze recipe (Bronze Nails from scrap) only needs 1 — so if you can already make nails, the level is not what is missing.
No recipe is attached to the Hardening Bucket itself — it is the anvil's extension, and the anvil recipes it unlocks are listed below.
The rest of this building tab
Building
Recipes
Build cost
Unlocked by
Wooden Anvil
15
Short Log ×1 Stone ×1
Bronze Works
Iron Anvil
30
Piece of stone ×4 Iron Ingot ×2
Iron Smithing
Steel Anvil
47
Steel Ingot ×4
Steel Smithing
Firewood shed I
1
Stick ×10 Bronze Nails ×2
Bronze Melting
Firewood shed II
1
Stick ×20 Bronze Nails ×6 Bronze Detail ×2
Firewood shed II
Furnace I
7
Piece of stone ×6 Brick ×12
Bronze Melting
Furnace II
10
Polished Stone ×6 Polished Bronze ×2 Brick ×16
Iron Forge
Bellows
—
Wooden Plank ×4 Bronze Nails ×4 Leather Scroll ×2
Bellows
Casting Table
—
Polished Stone ×4 Steel Ingot ×4 Steel Detail ×2
Steel Casting
Sluice Box
1
Board ×4 Bronze Nails ×4
Bronze Forge
Hardening Bucket
—
Wooden Plank ×4 Bronze Nails ×8
Bronze Craft
Buildings on one tab share the same material chain, so which one to build first follows from what you already have.
Where the inputs come from
Input
Used here
Produced at
Wooden Plank build cost
—
Woodworking Workbench I · Woodworking Workbench II · Circular Saw
Bronze Nails build cost
—
Wooden Anvil · Iron Anvil · Steel Anvil
“Used here” counts how often the input appears in this page’s recipes and build costs; “no producing row” means the recipe, alchemy and crop tables all come up empty — you gather, hunt, buy or loot it instead.
Common questions
What does the hardening bucket cost and unlock?
4× Wooden Plank + 8× Bronze Nails, unlocked by the Bronze Craft research (30 red tech points). No technology, level or item is a prerequisite beyond that research.
What is it for, if it has no recipes?
The bucket is the anvil's extension. Nothing is crafted at the bucket itself — every forging recipe runs at the Wooden, Iron or Steel Anvil — but 17 of those recipes carry the bucket as a requirement in the game data. Stand it beside an anvil and they become available there; leave it unplaced and the anvil keeps them locked.
What do I need before the bucket?
The research that unlocks it costs 30 red tech points, its parent 10 red, and the first node in that chain 5 red — 45 red from a standing start. That first node also brings the Wooden Anvil, Furnace I, the firewood shed and Bronze Nails from scrap; the last one hands over the bucket blueprint and the Bronze Detail recipe together.
Wooden Plank ×4 
Bronze Nails ×8 
Bronze Detail ×6 
Bronze Ingot ×1 
Iron Kit I ×1 
Iron Ingot ×1 
Bronze tools ×1 
Stick ×2 
Polished Bronze ×1 
Iron tools ×1 
Iron Detail ×2 
Advanced Detail ×2 
Steel tools ×1 
Steel Detail ×2 
Engineering Details ×2 
Bronze Axe ×1 
Iron Axe ×1 
Steel Axe ×1 
Steel Ingot ×1 
Bronze Pickaxe ×1 
Iron Pickaxe ×1 
Steel Pickaxe ×1 
Bronze Hammer ×1 
Iron Hammer ×1 
Steel Hammer ×1 
Bronze Shovel ×1 
Iron Shovel ×1 
Steel Shovel ×1 
Short Log ×1 
Stone ×1 
Piece of stone ×4 
Brick ×12 
Polished Stone ×6 
Leather Scroll ×2 
Board ×4