Stainless steel for knives | Knife steel - Hardness

Hardness of stainless steel and alloys for knives

The hardness of stainless steel and alloys for knives is usually measured on the Rockwell scale (HRC) and is one of the most important indicators of blade quality. It determines the steel's ability to hold a sharp cutting edge and its wear resistance, but at the same time affects its brittleness and the difficulty of sharpening.

The influence of hardness on knife properties

• Higher Hardness (60+ HRC):
  • Advantages: holds a sharp edge better and longer, higher wear resistance.
  • Disadvantages: harder to sharpen, higher likelihood of brittleness (chipping of the cutting edge).
• Lower Hardness (54 - 58 HRC):
  • Advantages: easier to sharpen, higher toughness and resistance to breaking and bending.
  • Disadvantages: loses sharpness faster, requires more frequent sharpening.

Steel hardness largely depends on the content of Carbon (C) and quality heat treatment (quenching). Chromium (Cr) provides corrosion resistance (if its content is ≥11.5%).

For kitchen and everyday carry (EDC) knives, a balance in the 57 - 60 HRC range is usually sought, as this allows the knife to be tough enough and easy to sharpen at the same time. For specialized tools, such as survival blades or high-end Japanese knives, steels with a hardness of 62 - 64 HRC may be chosen, sacrificing toughness for extreme sharpness and its long retention.