Glossary

Hardening steel means increasing its mechanical resistance. The steel is heated to a temperature of 750 - 1050 °C and is then usually quenched in water. At elevated temperatures, the existing lattice structure is "frozen" through this hardening process. The resulting internal stresses in the lattice structure increase the hardness of the steel. The cutler then heats the hardened steel again under very controlled conditions in order to achieve the desired compromise between hardness and toughness.

The process is also known as "tempering". A fine martensite structure is formed, which enables a high degree of sharpness. If the steel is overheated once hardened, the hardness can be reduced again, also known as "annealing". This is one of the reasons why Japanese knives are re-sharpened using watered whetstones. The hardness is measured in Rockwell C (HRC) and is specified for cutting steels.

This is what the structure or microstructure of hardened steel can look like.

Our entire range of knives is handmade from, among other materials, hardened steel.