A knife is an indispensable thing in many areas of human life. This is the universal subject that is constantly in demand. Knives are used in the household, fishing and active recreation, in construction, martial arts, etc. Without this item it is impossible to imagine a kitchen and a tourist set. Due to the fact that this tool is used so widely, there are many different types of knives: kitchen, tourist, universal, combat and others. There are also souvenir knives that attract buyers with aesthetic appearance.
In the process of permanent use of a kitchen knife, its blade may dull, sharpening the knife will return the blade excellent cutting quality.
What is a knife and what are its functions?
The knife itself is a tool for cutting various objects, consisting of two main parts: a handle that holds the cutting hand, and a blade with a blade on one or two sides. It depends on the sharpness of the blade the quality of the knife. Therefore, it is extremely important to know how to sharpen the knife. It is usually made from solid metals (stainless steel), which are sharpened by industrial methods. In combat models of knives, the blade end can also be sharpened. The handle is made of materials such as iron, wood, plastic.
The angle of the blade should be equal to 20 degrees.
The main property which any knife should possess, sharpness of an edge. Over time, any tool loses its former sharpness, so it is necessary to sharpen it from time to time. Convenience in working with the tool and quality of cutting depend on the correct sharpening. After all, a badly sharpened knife will not be able to cut wood, fish or bread. So do not underestimate the importance of the sharpening procedure for cutting tools.Back to table of contents
Steel hardness is an important parameter when sharpening a knife
One of the main indicators that determine the process of sharpening the knife and its quality, the hardness of steel. After all, a tool that is made of soft steel can easily be deformed or crumpled, and an overly hard material can crumble. Therefore it is worth choosing a knife with optimum steel hardness. Ideally, it should be 45-60 HRC. Such a parameter as hardness is extremely important for the sharpening process, because it determines the angle of sharpening the knife. The harder the blade, the greater the angle should be.
Diagram of blade cut elements: 1 - cutting edge (RK), 2 - feed, 3 - sharpening angle, 4 - descent, 5 - butt.
In the event that the owner of the tool is not aware of the hardness of the material, it can be fairly easily checked at home. Need to take a file with a small notch (file) and hold them on the blade of a knife. First, it must be done with a little pressure - with good hardness of steel, the file should slip freely enough along the sharpened part of the blade. If you press on the file with a noticeable effort, then it should slightly cling to the blade. In this case, the hardness of the knife is good and you can safely proceed to sharpening.
Before you start sharpening a knife, be sure to be patient. After all, the process of returning the blade sharpness can take from 5 minutes to several hours, depending on the type of knife. Therefore, you should not wait for visible results after a couple of minutes of sharpening.Back to table of contents
What are the grinding tools?
The first thing you need when sharpening a knife, grinding tool. Choosing a tool for sharpening is a very important matter, the quality of work directly depends on the correctness of its performance. To pick up the grinding tool is even more difficult than the knife itself. For sharpening, grinding and leveling the blades, such devices as mechanical and electronic sharpeners, grinding bars, musat, grinding belts, etc. are used. In case the knife, which requires sharpening, is expensive, then it is advisable not to save on funds for its turning. Since the tools for grinding cost a lot of money, it is important to immediately determine the best option, so as not to waste money.Back to table of contents
Bar for sharpening the cutting part of the blade
The higher the number on the bar, the larger the grain of the abrasive.
Bar for sharpening knives - quite an expensive tool. However, with it, you can achieve a really high quality sharpening. The main active ingredient, because of which there is a sharpness of the blade, abrasive crystals. They are almost invisible to the naked eye, but the result of their work is quite noticeable - a sharp knife blade. The more such crystals on each cubic millimeter of a bar, the faster and better the process of turning will be. Usually the number of these abrasive grains is indicated on the tool packaging. It should be borne in mind that for the quality of the grinding work requires at least 2 bars. One of them is used to give sharpness, and the other - for grinding. It is not recommended to purchase grinding bars, on the packaging of which the number of abrasive crystals is not indicated, since in this case it is impossible to determine the quality of this tool. It must be said that domestic producers often sin with the absence of such important information.Back to table of contents
Using musat for dressing and grinding
Musat able to maintain the sharpness of the blade, without resorting to sharpening.
Another tool widely used for sharpening knives is musat. It is a steel tube, similar to a file, a strip or a circle, with which it is ground, a knife is sharpened. In professional activities, this tool is used to a greater extent not for turning knives, but to maintain the correct shape and sharpness of the blade. Musat is great for working with kitchen knives, the blades of which, as a rule, are not too hard. This tool must be used before the knife has lost its sharpness, because you do not sharpen the blade with a musat, it is convenient for them to rule.Back to table of contents
Mechanical sharpener to make the blade sharp
In everyday life, such a sharpening tool such as a mechanical sharpener is often used. With it, you can easily work with kitchen knives and various types of scissors. The rather high popularity of this tool is due to the relatively low cost and ease of operation. The sharpening angle changes easily depending on the type of blade. The cutting part of the blade is sharpened quickly. But it is worth saying that you should not expect high-quality work from mechanical sharpeners. In addition, after using a mechanical sharpener, the knife may get blunt faster than before. Therefore, it is better to use it only for working with household knives, but not for hunting, tourist or combat, which require really high-quality sharpening.Back to table of contents
Electric Blade Sharpener
The electric knife is able to sharpen and polish the knife, automatically determining the optimal angle of sharpening.
Electric sharpeners are becoming more and more popular. They provide much better sharpening than their mechanical counterparts. Their undoubted advantages include not only the universality of the type of knife (kitchen, hunting, tourist, combat), but also by type of blade (wavy, straight). Working with such a tool is easy. He himself chooses the optimum angle of sharpening the blade. In addition to knives, you can sharpen and screwdrivers, scissors. An electric sharpener can handle a new blunt blade and an old one equally well. The degree of sharpness of the cutting part of the blade is also not important. The result of the work of an electric sharpener is maintained for a long time, the blade remains very sharp. Nowadays, such devices not only grind the blade, but also grind, rule and process it, bringing it to optimum condition. Such devices are very multifunctional! The only disadvantage of an electric little knife is its rather high cost. But the quality of the work definitely justifies its high price.Back to table of contents
Sharpening belts, abrasive and felt wheels for sharpening
Abrasive wheel should not be used at home, as there is a high probability of damage to the blade during the sharpening process.
Another way to sharpen the cutting part of the knife blade is to work with grinding belts, as well as abrasive and felt circles. This method of knife sharpening is used in the industrial production of cutting tools and their sharpening points. However, it is better not to start a newbie for this method, since knowledgeable professional people who know how to choose the right angle of sharpening and the speed of rotation of the disks work with him at the factories. Without this knowledge to sharpen the knife quality will not succeed. In inept hands, the blade can simply be deformed. The fact is that under the influence of the grinding wheel the blade heats up to a high temperature, as a result of which the steel must be hardened. But if you overdo the blade, it can simply deteriorate under the influence of temperature and friction. Another disadvantage of this method of making the blade sharp is its relatively short-lived effect. This is not surprising, because manufacturers and sharpening specialists are beneficial for the customer to contact them again after a while. Therefore, for the long-term effect, it is desirable to choose an electric sharpener.
So, summing up, it should be noted that any of the above methods is suitable for sharpening knives that will be used in everyday life, but for high-quality and long-term sharpening the blade of sports and other special types of knives it is necessary to use electric scissors and professional bars for turning.Back to table of contents
How to sharpen a knife correctly?
After the tool for sharpening has been chosen, it is necessary to become familiar with the process of turning and grinding the cutting part of the blade. After all, the result directly depends on the accuracy of turning. When grinding, you must start the process with a rough bar. It must be placed on a table or any other fixed surface. In order for the hard bar to not damage the surface coating, it is desirable to underlay a cloth or paper under it. It is necessary to process this blade until the barbnails appear on it - thin metal stripes running along the entire cutting part of the knife. After the burrs have appeared, it is desirable to change the grinding bar for a tool with a large number of abrasive crystals.
The blade of the knife should be perpendicular to the line of the cutting edge of the blade.
It is desirable that the bar was long enough (1.5-2 times larger than the size of the blade of the knife being sharpened). The pattern of grinding, at first glance, is quite simple: you need to hold on the grinding bar, directing the sharp edge of the knife forward. Care must be taken to ensure that the edge is as perpendicular as possible to the direction of movement that occurs when sharpening a knife.
The perpendicular angle of sharpening allows you to evenly sharpen the blade throughout its cutting part. The knife, which is sharpened along the entire cutting surface, to work much easier and faster. Another important geometric detail of sharpening a knife is the angle between the blade and the grinder. It is advisable to keep it around 20-25 degrees. Making the angle constant is hard enough. To ensure a constant inclination of the cutting part of the blade relative to the working surface of the grinding bar, you need to direct the handle of the knife up. It should be noted that for different types of knives may require a special angle of sharpening. For example, knives for cutting meat should be sharpened at a greater inclination than conventional ones. The only rule should be followed throughout the work - maintaining the same angle of sharpening.
You should sharpen the knife with a bar so that the tip of the tip at the end of the movement is at the point where the grinding surface ends. It is important that the blade under pressure does not come off the bar, because in this case it can be deformed or scratched. Some people make a big mistake in the pursuit of the speedy end of the sharpening process - they put a lot of pressure on the blade so that it will more rub against the grinding surface. This should not be done! Such actions lead to the loss of the angle of sharpening, but does not accelerate the process. The movement of the cutting part of the bar on the grinding surface should be smooth and careful so as not to disturb the angle of sharpening the knife and not to spoil your own work with an inaccurate movement. This whole process needs to be repeated a large number of times until the blade on each side becomes as sharp as possible. Over time, sharpening the blade will not cause any special difficulties, because in this case experience is extremely important.Back to table of contents
Grinding is an important step when working with a blade
The burr should look like an elastic thread and fly off after 5-6 kinks.
Sharpening the cutting part of the knife blade is not the only thing that needs to be done with the blade to give it maximum sharpness. After sharpening, the sharp part of the knife must be ground. Grinding the blade is necessary in order to maintain its sharpness for a longer time. By grinding with a knife blade, barbs are removed, which inevitably appear during the sharpening process. In order for the blade to remain as sharp as possible for a long time, it is necessary to ensure perfect smoothness of its surface. To grind the cutting part of the knife should be the same movements as when sharpening. However, the whetstone needs to be changed to the surface with smaller crystals. After the knife is ground and ground, its processing can be considered finished.
Sharpening a knife correctly is not at all a simple matter, it requires, above all, experience. Of course, if we are not talking about sharpening using an electric sharpener.
Work on giving the cutting part of the blade maximum sharpness requires utmost diligence and attentiveness, because all efforts can be nullified by one wrong move.
In addition, it is necessary throughout the work to maintain the correct angle of the blade. It is theoretically impossible to learn the technique of turning knives, because constant practice is needed.
It is easiest to give sharpness to the cutting part of the blade using an electric device for turning knives, scissors and screwdrivers, but such a tool is very expensive, so learning from manual sharpening on a mechanical sharpener, bars or various shafts is necessary at least from thinking about savings. A well-sharpened knife is a great tool and reliable weapon that is pleasant and convenient to use. Therefore, the result fully justifies the effort!