In the conventional selection of kitchen knives are usually also some models with a serrated edge. Typical representatives are saw and bread knives, but there are also small working knives with irregular cutting edge. With this type of blade, individual hollows must be ground out.
Elevations between hollows
A serrated knife consists of successive troughs, between each of which there is a blade elevation. If this elevation is flat and rounded, it is a bread knife. The more pointed the highest points, the more pronounced the serrated knife character.
Pronounced serrated knives, which also cut through meat bones, are often ground in a double row. In this case, both cutting sides are ground offset, thus doubling the number of saw teeth. Pretty much twice the grinding effort is required for them.
Grinding removal causes finite sharpening ability
When kitchen knives need sharpening, serrations are almost always among the objects involved. First, however, it should be checked to what extent sharpening is really necessary. Unlike the sharpening of straight blades, the number of possible sharpening passes is limited for wavy knife blades.
The respective material removal leads to changes in the ratio between trough and elevation. In the case of very old and already frequently ground blades, this can result in a change in the grinding angle. In extreme cases, the required angular dimensions can no longer be implemented. In this case, the entire serration must be redone.
Sausage-shaped beads or grinding bars
The shape of the individual troughs is rounded and concave. The width of each trough determines the diameter of the grinding tool that approaches the “sides” where the sharpness is created. Blades of this type can be sharpened only with grinding stones in the shape of discs, which have a specially made surface structure.
The discs have “sausage” shaped grinding beads. They must match the trough spacing of the knife blade. By using these tools, the cost of grinding remains moderate.
The alternative is to grind without a whetstone. Using a ceramic sharpening rod or a diamond file, the troughs must be ground out individually. Only experienced professionals achieve uniformity in this work.
Tips & Tricks
You can grind single-sided serrations relatively well yourself if you take your time. Double-sided serrations should be sharpened by an experienced sharpener, because it is almost impossible to achieve the required uniformity.