As promised, here we are with the second part of the guide for sharpening angles. Today, we will learn about different sharpening angles and when to choose which one.
Hardness vs. toughness: Before we dive into the details of the angles, it is important to understand the difference between the hardness & the toughness of the steel from which the knife is forged and how it affects the edge.
The toughness is the metal’s ability to endure fracture while hardness is what lets the metal resist de-shaping by penetration or indentation. The term also refers to its ability to resist bending, scratching, abrasion, or cutting. A good example is glass, which is very hard but not so tough (quite brittle).
While forging a knife the goal is to achieve the perfect balance between the two because if a knife made of steel that is too hard, it will be quite fragile and going overly soft means that the knife won’t hold an edge properly.
The sharpening range: The angles can vary quite a bit considering the core purpose of the tool.
10 to 17 degrees: The angle is quite low and is more suitable for knives that are not meant for chopping jobs. Fileting knives are more suited to this range.
17 to 22 degrees: A bulk of your kitchen knives will fall under this sharpening range. Knives with Asian origins mostly fall on the lower end of this spectrum; Japanese knives respond better to a 17 degrees angle. The angle you choose will depend on the severity of the job at hand. Although a knife sharpened at 17 degrees will cut very well, however, if you intend to put the knife through its paces then we recommend sticking with a 20-degree angle.
22 to 30 degrees: The higher the sharpening angle, the more durable the edge will be. However, it won’t be as sharp as a typical kitchen knife. These angles are reserved for tools or knives that get subjected to blunt force more often such as a pocket knife or a hunting knife.
More than 30 degrees: Most knives won’t benefit from this wide a sharpening angle. The goal of such angles is to prioritize durability & strength over acute sharpness. For tools that get sharpened at these angles, the cutting is achieved through momentum and force. Tools such as an ax, cleaver or machete come to mind as they require quite a bit of force and momentum to get the job done.