We only know the sharpest knife is best, but do you know the steel hardness scale of knife sets for the kitchen?
Hardness (HRC) - the ability of a material to resist penetration. Some people said the most common way to test the hardness of steel is to wipe the blade edges, the depth of the scratch on its surface determines the hardness. But this method is not scientific.
The modern science method is use the hardness tester. That is Rockwell hardness test.
The testing machine will uses the depth of diamond into the metal to determine the hardness, the greater the depth of penetration, the hardness is smaller.
Generally, the blade hardness of a good knife should be above 50HRC and below 60HRC of Rockwell hardness.
In short, the hardness is higher, the wear resistance is stronger, but also about the brittleness. Non-steel alloys, such as satellite, are lower in hardness, only about 40HRC, but they also have a high wear resistance.
The material knife set for the kitchen is rolled steel, stainless steel, carbon steel or zirconia, Damascus, etc. But the steel hardness scale is only for the knife blade.
Different knife blade hardness is depend on different material, so is it possible to understand that the higher hardness, the higher sharpness?
The answer is partly true, because the "cutting fast" also depends on the edge of the blade, softness and so on. Such as the ceramic knife is more hardness than stainless steel, but the user found the cutting fast of stainless steel kitchen knife is faster than a ceramic knife when used.
Because it limited by the material, the edge of ceramic blade should not be too small, otherwise it will be brittle.
Hardness: 3cr13<4Cr13<5Cr15<8Cr15<9Cr15≈Carbon Steel<Damascus <Ceramic (Zirconia)
Hardness is 56hrc for a normal kitchen knife, 58hrc for very nice and 60hrc for the top level.
Surely, more hardness or higher material on the knife, the price you buy is more expensive.
But now you know the steel hardness scale details, you can choose the knife set in the kitchen easily.