Softer steels require sharpening more often, but they are much easier to sharpen than harder steels. Some users like a softer steel, in the 54-56 HRC range. This chart is by no means a hard and fast rule, merely an example of typical numbers you might expect. Sometimes this is the case, but it is not always what you want, as I will explain in the Softer Steels section below.īelow is a chart showing approximate Rockwell numbers you can expect from different types of blades. Many will judge the quality of a steel based on the Rockwell number, with the perception being that higher numbers indicate higher quality steel. How often are you willing to sharpen it, and what kind of use did you want to use it for (slicing or chopping, etc.). So, then it comes down to preference and blade use. On the flip side, the harder the steel, typically the more brittle it is as well. The better edge retention, the less often you must sharpen it. The harder the steel, the better edge retention it will have. The higher the number, the harder the steel is. Look at my Steel Chart to see what ranges a particular steel usually performs best at. However, most steels have a range in which they perform best. The exact same steel can be hardened (or tempered) to both a low number, or a high number. But I shall endeavor to give some good rules of thumb. This question is somewhat complicated as the most accurate answer is: it depends. This YouTube video by Materials Science 2000 provides a great explanation of the Rockwell Hardness test: This test is performed by measuring the depth of penetration of a diamond tipped indenter under a large load compared to the penetration made by a preload. The important scale for knife steel is Hardness Rockwell Scale C, often shown as HRC, which is further abbreviated to just Rc.

There are different Rockwell scales of hardness. I won’t go into the history of the Rockwell scale, as it is easily learned on Wikipedia. The test does little to no damage to the material being tested, and provides important information about the hardness and durability of the steel.

The range should never be greater than two, in a reliably quality controlled setting. When a range is listed, it means that whatever variation occurs in the hardening process will fall within that range. The Rockwell hardness test is the industry standard for knives. An example is stainless steel AUS-8, which usually 57-59 Rc. The Rockwell rating is a scale that is used to measure the hardness of a material. This number represents the Rockwell Rating. When looking at knives you will often see a number in the specs with “RC” after it.

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