Primer for quenching and tempering

[Maelstrom]

After working out the ins and outs of quenching my tools (and much frustration with shattered items) I thought it would be kind to put down the basics to quenching and tempering items. 
All temps are Celsius.

Quenching
1. Quenching improves either the durability or the "power" of the finished work.  Power can be either damage inflicted or speed depending whether the item is a weapon or tool
2. To improve power heat the item to the temp in the tool tip (815 to 1050 for iron).
3. To improve durability add some fire clay to the item before heating to the same temp for power quenching.
4. Quenching uses one durability on the tongs.
5. Quenching a tool has a chance of breaking the tool and increases with each quenching.

Tempering
1. Tempering can only be done after quenching an item and reduces the break chance on the next quenching. 
2. To temper a tool it must be heated to at least 550 but no more than 700 and let it air cool.  DO NOT USE WATER!!!
3. An item is tempered once the temperature has dropped below 200.  Once the tool is at 199 fire clay can be added if desired but it can then be heated for a quenching.
4. It is highly recommended to temper a tool if you want to quench it more than once.

Some helpful tips, aka pro tips
1. Moving the tempered item in the inventory can instantly reduce the temperature by a maximum of 100 degrees.
2. If an item is heated beyond a desired temp (either the max for quenching or tempering or significantly higher than the bottom temp of the range) you can dip it briefly in water to reduce the temp without loosing the quench or temper.
3. Consider quenching an item no more than 4 times.  Of the few dozen times I've quenched a tool it is exceedingly likely it will break on or before the 5th quenching.  Pretty strange considering that the break percentage is only 14.6% for the 5th quenching.  Your mileage may very.
 

[Kiler_]

Quenching is frustrating. I've had 3 steel axes shatter in a row on the first quench.