There are situations when adding scallops can improve both circular knife blades and straight blades.
For the purposes of this article, we’ll be looking at scallops on circular blades. Keep in mind, scallops can be added to straights blades too.
What do scallops do?
In most uses, scallops create a more aggressive cutting action and increase the life of a circular knife blade.
What is a scallop?
Scallops are sharpened recessed curves found on the edge of a circular blade. Sharp points are found at the leading edge. This means, in the same space, there’s more linear cutting surface than on your standard beveled-edge blade.
More Aggressive Cutting Action – Scallops’ aggressive cutting action comes from a rocking motion caused by its unique shape. The point of its curve penetrates the material that’s being cut. As this is happening, the center of force shifts exposing the material to more area of the curved part of the blade. This means that the material being cut receives a wide range of cut angles. This wide range of cut angles is why a scallop cuts so aggressively.
Longer Blade Life – The points on a scallop lessen the amount of force needed for the rest of the blade to make the cut. In other words, the points help protect the curved part of the blades, thus the entire blade wears more slowly. Scallops also increase the cutting edge length by up to 35 percent. Most of the time, these two things—reduce edge wear and increase cutting edge—result in longer blade life.
Hyde makes circular knife blades with two kinds of scallops, pointed and wavy.
Pointed Scallop Design – Arcs are ground into the blade’s edge. When two arcs join together, they form a defined point. Hyde recommends this design for materials that are difficult to cut and when the speed of the cut is a consideration. Circular knife blades with this design are common in the food processing industry.
Wavy Scallop Design – This design doesn’t have points. Instead it has smooth arcs. Wavy scallop isn’t as aggressive as pointed scallop but it’s still more aggressive than a beveled-edge blade. This design is ideal for materials that are tough to cut but might otherwise break the tips of a pointed scallop. Also, wavy scallop design is great for textiles because their cuts are very smooth.
Hyde suggests that you use scalloped-edge circular knife blades for all your tough cuts: fiberglass, leather, reinforced hydraulic hoses, rope, seat belts, and Teflon, just to name a few.
