Is Your Knife Dull? Measuring Sharpening Correctly

A dull knife does more than just slow down your work and make it less efficient. Such a tool becomes dangerous because due to the insufficient sharpness of the blade, you have to put more effort into cutting, which can lead to cuts and other injuries.

Manufacturers sharpen knives when they make them, so a new knife is always sharp. But in the process of use, the edge will sooner or later become dull. The user's task is to recognize a dull knife in good time and restore its sharpness.

In this article, we will describe in detail when you need to sharpen a knife and how to measure the sharpness with the help of improvised means, without risking injury. In addition, the same methods can be used to check the quality of the blade after processing with a sharpening device or on a water stone.

Is a sharp knife dangerous?

All experts who constantly work with kitchen, hunting, carpentry, or other knives clearly say that a properly sharpened blade sharpening is safer than a dull one. If the specialist is skilled in handling the knife, the likelihood of getting a cut is minimized.

This is because when working with a sharp knife, you need to apply less pressure to cut food or other objects. If the blade is sharp, it behaves more predictably and moves along the expected path.

One of the most popular questions is how often you should sharpen a knife to avoid using a dull blade. It cannot be answered unambiguously. The sharpness of the blade depends on the hardness of the steel and the objects it cuts, frequency of use, care, storage method, and other factors.

Most chefs agree that it is better to sharpen or hone the knife as soon as you detect the first signs of blunting. This is typically once a week in professional kitchens and once a month in home kitchens.

Note that Japanese knives are made of steel with a hardness of 58-63 HRC, while European knives are made of steel with a hardness of 52-56 HRC. This means that Japanese tools will stay sharp a little longer with the same intensity of use.

You also need to remember that sharpening is the processing of a knife on an abrasive stone or with the help of special sharpeners. In this case, part of the steel is removed from the blade to restore sharpness. This process should not be confused with straightening the cutting edge line using a honing rod. It is best to hone a knife after each use.

Ways to check the sharpness

For fast and safe cutting, it is essential to ensure that the knife blade is completely free of defects:

• chips;
• rolled edge parts;
• burrs.

The cutting edge itself is a narrow line at the very edge of the blade. It can be from a millimeter to several microns wide. The size does not affect the sharpness. But the basic rule is perfect flatness and the same thickness of edge along its entire length.

The easiest way of measuring how dull a knife is - is to inspect that part of the blade. To do this, place the edge in front of the light source and examine the glare on the blade. In the best case, the reflection should be visible along the entire length, forming a uniform line. If the light is reflected only in some parts, it is high time to sharpen the tool.

However, only professionals can identify the appropriate sharpness by eye. Here you need to take into account the sharpening angle and other factors. Therefore, there are other methods of sharpness measuring and testing.

A piece of paper

A simple, affordable, and effective method of testing. You will need a sheet of thin printing paper or a store receipt. To do this test, hold the paper in an upright position and move the blade across to cut it. If you can cut the strip without jamming or ripping the paper - your blade is in excellent condition.

Another way is to take a few newspapers or a magazine, roll it into a tube, and try to slice it like a sausage. If the blade is sharp, it will easily cope with the task. When cutting, the tube will not bend, and the cut will be smooth and without jagged edges.

Tomatoes

This vegetable has a thick rind but a soft pulp. When the blade is sharp, it can cut the fruit into very thin slices. If the blade is dull, the slices will be sloppy and torn, and you will not be able to cut the rind with ease.

Conclusions

You can sharpen a dull knife on a water stone made of abrasive materials. However, we only recommend this method to professionals who know how to handle whetstones and maintain the desired angle of sharpening the blade.

For both professionals and beginners, the TSPROF sharpening system will be the best choice. This is a special device that securely holds the blade in the desired position. It is enough for the user to drive the sharpening stone along the knife until it is sharp enough. The sharpening angle remains fixed the entire time, unless you need to change it, which is very convenient, due to the presence of a built-in angle finder and the angle-adjusting mechanism.