Rockwell hardness describes how resistant a knife’s steel is to permanent indentation. It is usually expressed as HRC, meaning the Rockwell C scale.

To measure it, a diamond-tipped indenter is pressed into the steel under a controlled load. The machine measures the depth of the indentation: the shallower it is, the harder the steel.

Most kitchen knives fall between approximately 54 and 64 HRC. Softer steel is generally more malleable, loses its edge sooner but thankfully is way easier to sharpen and maintain an edge and is less likely to chip. Harder steel can hold a finer edge for longer, but may be more brittle and much more difficult to sharpen, requiring coarser abrasives and longer time.

Rockwell hardness is useful, but it does not determine knife quality by itself. Steel composition, heat treatment, blade thickness and edge geometry are equally ( if not more ) important. A higher HRC number does not automatically mean a better knife—it simply describes one characteristic of the steel.

Here's a useful guide by brand-

Victorinox ( generally on the softer side ) 55-56 HRC

Global,Zwilling,Wushof and Robert Welch 56-58 HRC

Shun 60-61 HRC

Miyabi 63-66( though some carbon steel models are much softer )