BALANCING THE ROCKWELL HARDNESS SCALE
If you’re looking at knife specs, you’ll often see the term Rockwell hardness or the abbreviation RC. The Rockwell rating is a scale to measure the hardness of a material. In the case of knives, it measures the hardness of steel. The steel is tested by using a diamond-tipped indenter on the steel and comparing the penetration with known variables.
In knife steels, you often see numbers ranging in the high40s to low-60s. The lower the number, the softer the steel. Softer steel can be stronger and less likely to chip or break, but will not hold a sharp edge long and thus, will need to be re-sharpened more often. High hardness will offer excellent edge retention, but can be much harder to re-sharpen and can, at times, be brittle.
Generally, you’ll only see numbers in the 40s on items like throwing knives that don’t need much of an edge but need toughness. Typical pocket and hunting knives run in the mid-50s, with specialty steels creeping up into the high-50s and low- to mid-60s.
If you want a more thorough read on Rockwell hardness, check out A.G. Russell’s website (Agrussell.com). He has the best breakdown on the topic that I have ever seen.