The Tempering (Carbon)
Tempering gives hardness to the knife to ensure a long lasting cutting edge. It’s a very important operation.
The knives are carefully placed in special trays. They are put into the furnace at 820° centigrade.
After a period at these high temperatures, the knives are immediately placed into oil.
The knives are then put back into the furnace to "return" hardness to the steel (200°-300° C).
For the Carbon Knives, we verify their straightless, one by one.