Learn more about the scale that sets your Knife a cut above.
If you have spent any time at all in the kitchen, you’ve probably noticed that all kitchen knives are not created equally. Since there are many types of steel and processes of knife-making, there must be a knife material rating system so that professional chefs and home cooks can easily compare types of kitchen knives.
The Rockwell Hardness Scale is the system used to determine the precise strength and sharpness of steel for knives. When looking for the best blade, this scale can tell you everything from which kitchen knife is made from harder steel to which offers a sharper cutting edge.
Created by Stanley P. Rockwell in 1914 as a new way to measure the steel ball bearings manufactured at his company, the Rockwell hardness test was eventually found to apply to any type of metal as well as non-metallic materials.
Today, the Rockwell Hardness Scale is the standard method to measure and determine the strength and quality of a kitchen knife blade.
The Rockwell Scale is used to determine the hardness of a metal by measuring the depth of the indentation made after a conical diamond impacts a piece of metal. Since diamond is the hardest natural substance on the planet, it is the perfect choice to use for the test impact.
The test is performed twice. During the first test, a minor amount of pressure is applied to the metal and the indention is measured. During the second test (in the exact same position), the pressure is then increased to about 300 pounds and the diamond-shaped indentation is measured again.
The difference between the first indentation depth and the second indentation equals the hardness of the knife blade. Since the hardness of steel does vary greatly, many manufacturers offer a hardness rating range for their steel knife products for easy recognition of its qualities.
There are actually 30 different Rockwell scales that are used to determine the hardness of a kitchen knife. They all use a unique combination of testing variables including different forces as well as different types of indentation.
Once a knife is made, it is given a Rockwell Score rating because this score is known to be standardized, fast, and reliable. The Rockwell scale uses letters of the alphabet for ratings.
The most important Rockwell scale for measuring the steel of knives is the Rockwell C Scale, often shown as an HRC score. When using an HRC score, the steel’s resistance to permanent distortion is being measured.
A great example for hardness standards on the Rockwell scale is to assess the HRC score of a typical ax with a sharpened edge, which is around 50 HRC when it can cut through a piece of wood without any issues. Here are the HRC scores for kitchen knives:
The best rating for kitchen knives is an HRC score between 59 and 64. Any score above this would make the knife blade extremely brittle, which means that the blade could actually break while using it.
Professional chefs as well as experienced home cooks will want to choose a kitchen knife that has an HRC rating of 55 and higher for best results when cooking. For reference, all Made In Knives have an HRC score of 58+.Qualities of Low RC Ratings
Because every Made In Knife has an HRC of 58+, you know you’ll be getting a strong and durable Knife that’s still easy to sharpen and maintain. Through knowing more about the Rockwell Hardness Scale, you’re now able to confidently shop for a kitchen knife that makes mincing, slicing, dicing, and prepping ingredients a breeze.