The teeth on the back of a knife blade are called a "serration" or "serrated edge." A serrated edge consists of small, scalloped, or saw-like notches along the back or spine of the blade. These notches create points that can cut through materials with a sawing motion.
Serrated edges are commonly found on various types of knives, including bread knives, steak knives, some utility knives, and survival or tactical knives. They serve specific purposes and have some advantages and disadvantages compared to plain (non-serrated) knife edges.
Advantages of serrated edges:
Cutting tough materials: Serrated edges are highly effective at cutting through tough or fibrous materials, such as bread crusts, tough-skinned fruits, or vegetables with thick skins (e.g., tomatoes).
Less maintenance: Serrated edges tend to stay sharp longer than plain edges because the teeth distribute the cutting force over a larger area. As a result, they may not require frequent sharpening.
Utility during emergencies: Serrated edges can be useful in survival situations where one may need to cut through ropes, cordage, or other sturdy materials.
Disadvantages of serrated edges:
Precision cutting: Serrated edges are not ideal for tasks that require precise slicing, such as thinly slicing meats or delicate ingredients, as they tend to tear rather than cleanly slice through.
Sharpening challenges: Sharpening serrated edges can be more complicated than sharpening plain edges. Special tools, like tapered or round sharpening rods, are needed to maintain the proper angle of the serrations.
Difficulty in cleaning: Food particles and debris can get trapped in the serrations, making them more challenging to clean thoroughly.
In summary, serrated edges are excellent for specific cutting tasks that involve tough or fibrous materials, but they may not be as versatile as plain edges for everyday kitchen or general-purpose use. For most cooking and cutting needs, a well-maintained plain edge knife is often preferred. If you have both types of knives, you can enjoy the benefits of each edge design depending on the task at hand.