Quenching and tempering let you improve iron, meteoric iron, and steel tool and weapon heads before assembling them. The mechanic also works on some complete items, and the process is the same.
Before quenching, decide which of the two bonuses you want. Fire clay increases durability, while quenching without clay raises power, and that power boosts both damage and mining speed. You can't get both bonuses from the same quench. Each later attempt carries a higher shatter risk, but tempering can bring that risk down.
Tempering lowers the accumulated shatter chance, but it also reduces the power bonus gained from quenching. The durability bonus remains unchanged.
Required Materials
- a forge;
- charcoal, brown coal, black coal, anthracite, or coke;
- bellows;
- a water source — either a water block or a water-filled barrel;
- fire clay — optional.
Only a forge and fuel are required for tempering.
How Quenching Works
First, decide which property you want to improve with quenching.
Coat the head with fire clay in the crafting grid while it is no hotter than 250 °C, and quenching will raise its durability. Leave the clay on when you heat it. Leave the head uncoated if you want quenching to raise power instead.
1. Apply Fire Clay
You can skip this step. Use fire clay for a durability bonus. If you want a power bonus, leave the tool head uncoated.
2. Heat the Tool Head
Place the tool head in a forge and add fuel. Light it. Without bellows the forge cannot reach the quench window, so use the bellows to heat the head to between 815 °C and 1050 °C.
3. Cool the Tool Head Quickly
Do not go above 1050 °C: there is no bonus past that, but the piece can still shatter when you cool it. Take the head out of the forge and quench it at once in a water block or an open barrel of water. A sealed barrel, and a barrel of salt water, will not do it.
For the quench to count, cool the item to 200 °C or below in less than 0.25 in-game hours. At the default calendar speed that is about 30 seconds. The sizzle stops earlier, near 220 °C, and the splash keeps going after the quench has already succeeded. Watch the temperature.
Shattering Risk
The first quench has a 5% shatter chance. Each successful quench adds exactly 5 percentage points to the risk of the next one. Without tempering, the sequence is 5%, 10%, 15% and onward.
You can quench an item as many times as you like, but each success raises the shatter risk and adds a smaller bonus than the one before.
The shatter risk applies only to quenching. Tempering itself cannot destroy the item.
After a successful quench, the tooltip shows the bonus and how many quenches the item has had. If it shatters, the whole head or complete item is gone and no metal comes back. That can happen while it is still cooling in the water.
How Tempering Works
Tempering reduces the shatter risk that builds up from quenching.
Tempering works like quenching, but at a lower temperature and with much slower cooling. After heating, leave the item to cool in the air.
1. Heat the Tool Head
Place the tool head in a forge, add fuel, and heat it to between 550 °C and 700 °C.
2. Allow the Tool Head to Cool
Take the tool head out of the forge and let it air-cool to 200 °C or below. The cool has to take more than one in-game hour. At the default calendar speed that is more than two minutes. Dunking it in water right away does not count as a temper, and it does not shatter the item either. Above 815 °C the item starts quenching instead. It can cool on the ground or in your hand.
A successful temper lowers the shatter risk of the next quench. The durability bonus stays the same, while the power bonus decreases a little.
The first temper reduces the current shatter chance by exactly 20%. After one quench that is exactly from 10% to 8%. The power bonus drops by exactly 8% of its current value. Later tempers are a little weaker. You cannot temper an item more times than it has been successfully quenched.
Results of the First Quenches
Each successful quench adds a smaller bonus and raises the risk of the next attempt. To start with, the first three results are the ones to know:
- Without clay or tempering: the power level bonus is +10% after the first, +18.3% after the second, and +25.5% after the third successful quench.
- With fire clay: the durability bonus is +20%, +36.7%, and +51%, respectively; tempering does not reduce these values.
Tips
- Use fire clay when you want to increase durability.
- Do not use clay when you want to increase power.
- Carefully watch the temperature before quenching and stay between 815 °C and 1050 °C.
- Once cooling starts, get the item to 200 °C in less than 0.25 in-game hours. Do not wait for the sizzle to stop: it ends before the quench succeeds.
- Use tempering before another quench to reduce the accumulated shatter chance.
- Remember that tempering reduces the power bonus but does not reduce the durability bonus.
Quenching and tempering were added in version 1.22, along with iron and steel spears.