Knives come in all sorts of shapes and sizes, and they can also be distinguished by what they are primarily used for. One of the biggest differences that can be used to identify a knife type is its blade, with the most common being the straight blade and the serrated blade. The questions often asked are why certain knives have serrated edges, and what purpose a serrated edge knife has.
Read on to find the answers to these questions and other facts about serrated edge knives, including why they are preferable to straight blades in many circumstances.
Perhaps the first thing we should do is to define what a serrated knife is and how its design differs from other knives. If we start with a straight edge knife it is fairly simple to describe this as a knife with a sharp-edged blade that has no indentations or any other type of machining on it. If you think of the blade on a Stanley knife or that of a normal pen knife, these have straight edges.
With serrated knife, instead of the blade's edge being simple and straight, it will have been machined along its length to produce indentations or teeth as they are often called. The effect of this is to produce peaks and troughs along the edge of the blade. The most common items with serrated edges are tools such as a wood saw, and with knives, the most obvious example is that of a bread knife, although there are many others.
On a serrated blade, you have teeth, although they are often given other names such as peaks, serrations, saw teeth or cutting points. Whatever they're called, simply regard them as the peaks of the blade as you look along its length. These peaks are normally very sharp and of course, they are prominent too. Depending on the tool that a serrated edge is on, the distance between those peaks will vary — from very wide gaps on band saws to fractions of an inch on knives used for more intricate cutting jobs.
Obviously, if we have peaks, there will also be troughs, and these can vary in size and shape, with some smaller blades having 'V' shapes, and on larger blades the troughs look more like 'U' shapes. When a serrated blade is being used for cutting, with the forward thrust the teeth will cut through the material, and this is repeated on the backward stroke too.
One downside to serrated edge knives is that the cuts they make can be less clean and precise than a straight edge knife simply because it is effectively hacking through the material versus the slicing action of a straight blade.
There are different ways in which a knife is used to cut through a material. One way is a 'push' cut. This is where you push the knife through the item which you are cutting. A simple example of that is when you cut through an apple, chop vegetables or carve wood. Normally, when you are cutting something using a push cut, a straight-edged blade is preferable. as you can control it, and it also produces a much cleaner cut.
With a serrated edge blade, the cutting action is more of a slicing or sawing motion, whereby you are driving the length of the knife back and forth through the material. In this way when you are moving back and forth it is the individual teeth of the knife that are doing the cutting rather than the entire blade length as is the case with a straight blade.
The most popular use of serrated blade knives is in food preparation. They are ideal for cutting through the types of skins you find on citrus fruits and tomatoes. Sticking with food, if you have eaten streak, then you'll know that the easiest way to cut through it is with a serrated steak knife.
Cutting bread is made so much easier with a serrated knife than it would ever be with a straight edge knife, which would be unlikely to be able to cut through the crust.
Serrated edge knives also have uses outdoors, especially when you need to cut something which is very tough. such as dry or wet rope, or thick fabric. They can also be used to cut through tree bark and sticks to produce firewood or makeshift tent stakes.