Production

From blank to knife

ZWILLING J.A. HENCKELS has optimised the hardening process. FRIODUR®, a protected brand name of ZWILLING J.A. HENCKELS, identifies products whose steel has been specially ice-hardened. This process involves four important stages of heat treatment:

1. Heating up the steel to more than 1000°C
   Heating up improves the molecular structure for the benefit of higher hardness.
   Higher hardness = longer lasting sharpness
   
   
2. Cooling down to room temperature.
   The cooling harmonizes the molecular structure, takes pressure off the material and ensures an especially flexible stability. This adds safety when used and prevents blades from breaking.
   
   
3. Freezing to -70°C.
   Ice-hardening strengthens the corrosion resistance and thus protects better against rust.
   
   
4. Reheating twice to just below 300°C.
   The reheating harmonizes the molecular structure and takes pressure off the material.

The result: Exceptional hardness, high elsticity and very high corrosion resistance.

Further processing

Final shaping is achieved by grinding. Surface treatment, producing the desired finish, is accomplished by:

• grinding
  
• finish-grinding
  
• dry-fine grinding
  
• polishing

3. Assembly

The assembly involves joining the prefabricated blade and handle to complete the actual knife.