Knives are the oldest tools created by man and have had a significant impact on the development of many civilizations. To this day, they are indispensable for performing many household and professional tasks. Their diversity is truly amazing; there are different types of knives for certain types of work. However, they all need sharpening. If you do not sharpen the blade for a long time, it will begin to dull and lose all its cutting properties. To ensure efficiency, it is necessary to provide for timely sharpening of tools and maintain the correct sharpening angles of knives depending on their purpose.
Sharpening features
During the manufacturing process, based on the professional goals and purpose of the tool, a certain blade shape, thickness parameters and inclination of the cutting edges are selected. It is thanks to the correct inclination of the angles and position of the blade that the most stubborn textures can be processed, since the correctness of the cut is ensured only if certain working positions of the tools are observed.
Optimal knife sharpening angles require maximum pressure on the cutting materials during operation. If the tilt changes, the blades can easily be damaged. It is important to note here that each blade model needs to be sharpened with strict adherence to certain angles. Based on what design features the knife has and what use it is intended for, the optimal sharpening angles are determined.
At the same time, it is undesirable to process some types of professional or chef’s tools (Tramontina and Lansky) yourself; this should be done by a qualified person using special equipment so as not to damage the blade.
Wave sharpening
Today, many knife manufacturers produce models with rounded blade teeth . The debate regarding the advantages of one or another sharpening tooth shape reveals some important aspects of the use of these blades. For example, it is absolutely known that the sharp edges of bends are designed for tougher work . By cutting the material, they actually tear the surface, easily penetrating it with sharp ends. And with great force they provide maximum cutting depth . The rounded edges of the bends, on the contrary, cut more than tear, however, this uniform cut, which does not separate the woven fibers, is also very effective for cutting highly fibrous materials, such as ropes and cables .
An important point is also what side of the blade the wavy sharpening is made on . When cutting from top to bottom, this issue does not matter. However, if you cut away from yourself, which is always recommended from a safety point of view, then for a right-handed person the sharpening should be located on the right side of the blade, when looking at the butt, and for a left-handed person - on the left. This will ensure the ideal cutting angle .
The wavy sharpening of the blade blade , located on the left side, is found, for example, on all models of knives. This is due to the fact that in the 80s, founder Sal Glesser came to the conclusion that the wave-shaped sharpening located on the right side of the blade moves the blade to the left when cutting. And in this case, given that most users are right-handed, there is a high probability of accidentally injuring a person when working with such a knife, which can have a very negative impact on the company’s image in the event of legal disputes about the dangers of using the company’s products. Therefore, he decided to place the sharpening on the left side of the blade. In fairness, it is worth noting that in fact, a very small proportion of products are used in the kitchen for cooking.
What is the sharpening angle of a knife
Often, this value is rarely indicated in the technical specifications for a particular tool when purchasing it, although it is one of the important criteria that affects the cutting property of the tool. The lack of relevant information may cause some difficulty for the owner in understanding at what angle to subsequently sharpen the tool. To avoid this, you can use the table below for sharpening angles of knives. However, before that, let's figure out what this value actually is.
The area where the slope on the blade smoothly meets the edges of the cutting edge is called the approach. The angles of convergence of the approach on the two sides of the knife blade are called the “sharpening angle.” Ideally, the blade may have no leads; in such cases, sharpening angles are called trigger angles. But instruments with such a design can be found quite rarely. These mainly include products such as professional Japanese kitchen knives.
The sharpening angles are directly responsible for the purpose and type of work for which the knife was created. The smaller the sharpening angle, the easier it is to cut and the knife becomes sharper, but it quickly becomes dull and needs to be sharpened again. The greater the sharpening angle, the more similar the blade becomes to an ax and the longer it keeps its sharpness.
Theory, practice and interesting features of the serrated blade
The practicality of using a serrated blade has been noticed for quite some time and is not something innovative. Paying attention to the world around us, you can see that nature itself gives clues on how to make it more convenient to perform many different tasks. For example, shark jaws have a “natural” serrator . Shark teeth are excellent at capturing soft material such as the flesh of an animal or fish, tearing and cutting it into pieces for convenient absorption. In addition to the shark, many wild animals and fish, adapting to the surrounding survival conditions, acquired the necessary structural features of the jaw with areas of especially dangerous rows of sharp teeth .
You can also pay attention to the tools of primitive man. As is known, primitive man was forced to master stone and wood to create the first tools. Even on these primitive tools made of petrified wood, a contemporary can see the tooth-like sharpening of the cutting edge of a primitive knife . This piece of petrified wood comes from Cairo, Egypt and is estimated to be from the Egyptian Neolithic period 5000-4500 BC.
Many knives designed for special purposes have serrated blade sharpening. So, for example, a sling cutter, in addition to the main purpose of cutting, is also intended for cutting parachute lines. And special knives of rescue services in many countries necessarily have a serrated area of the blade blade for quick and effective cutting of ropes, cords and seat belts. Underwater, tourist, combat, and self-defense knives, as a rule, have a blade section with a serrated blade. This is especially true for underwater knives, since in conditions of the need to quickly complete tasks of cutting cords, ropes or cables, as well as taking into account the increased weight of physical movements under water, double physical activity, so to speak, nothing can be better than a serrator .
Quite often, a serrated blade is used in kitchen knives . As a rule, a fine serrated tooth (tooth length up to 1 mm) is used on the blades of kitchen knives designed for cutting soft foods, such as ripe tomatoes. Serrated blades are also used in kitchen knives for cutting bread. In fact, even an ordinary blade with a smooth cutting edge is also a serrator. Only the teeth of this serrator are very small, they can only be seen under a microscope. You may have noticed that disposable cutlery (plastic knives) are also made with a serrated blade profile, since a soft material such as plastic does not allow for an acceptable other cutting edge shape.
The depth of the cut with a serrated blade depends on the shape, size and angle of the wave-shaped sharpening. As a rule, one wide bend is followed by two narrow ones, which definitely gives the blade improved cutting practicality. The cutting teeth of such a blade can have either sharp or rounded curves. Examples of knives with a pointed wave-shaped sharpening are models, “Micro Tech”, “Gerber” and others.
In the knife industry, serrated teeth became a characteristic feature of tactical knives after the Mariner models with wave-shaped sharpening of the blade began to be sold. Moreover, this characteristic now applies not only to knives with a fixed blade, but also to folding knives. However, when giving a knife with a serrated blade the feature of a tactical knife, you should remember that for this you need to take into account the shape of the wave-like sharpening and its location on the blade, as well as the presence of other components of the tactical knife. Therefore, all knives with a serrated blade should not be considered tactical knives.
Table of sharpening angles for different types of knives
In order to perform high-quality processing and maintenance of tools, it is necessary to maintain the basic sharpening angles of knives for various types of tasks with their use. To control the correct sharpening of corners, you can use a table that presents recommended values for various types of knives:
| Knife types | Sharpening angles |
| Dining rooms for serving | 55° — 60° |
| Kitchen household | 30° — 35° |
| Kitchen professional | 25° — 30° |
| Chefs professional | 20° — 25° |
| Cutting for fish | 25° |
| Cutting machines for meat and large fish | 30° |
| Vegetable cutters | 35° |
| Fruit | 10° — 15° |
| Cutting for root vegetables | 22° — 25° |
| Boning machines for meat | 25° — 30° |
| Chopping axes | 25° — 30° |
| Sirloin | 10° — 15° |
| Penknives | 20° — 25° |
| Tourist / hunting, priority is spiciness | 30° — 35° |
| Tourist / hunting, wear resistance is a priority | 40° — 45° |
| Shoe repair | 30° — 40° |
| Shoe cutting machines | 20° — 25° |
| Universal carpentry | 30° — 45° |
| Chopping (machete) | 45° — 60° |
Materials used for kitchen knives
The most common, frequently used and indispensable types of knives in the household are kitchen knives. In the home kitchen, various types of knives are used, it all depends on the hobbies and wishes of the owners. In professional kitchens in restaurants and cafes, the use of professional kitchen tools is practiced. Such sets are a whole range of blades that differ in design and functionality. They also differ depending on the material from which they are made.
Among the most common materials are the use of:
- Carbon steel. It is an iron and carbon alloy containing the addition of vanadium or manganese. Over time, the surface of such blades rusts and becomes stained.
- Of stainless steel. An alloy with iron, carbon and chromium, to which inclusions of molybdenum or nickel are added. Such blades must be constantly sharpened; after the metal becomes tarnished, the knife begins to become unusable.
- High carbon stainless steel. It is a combination of carbon and stainless steels, which contain vanadium additives, molybdenum, and cobalt. They have increased strength, the period of blade sharpness is increased.
- Damascus steel. It is a blacksmith forging, for which different types of metal are used, with a series of hard and soft alloys. The use of such material is expensive and is often in demand among professionals. Damascus is used to produce hunting knives, collectible blades and razors. Sharpening of such blades is carried out exclusively by hand along the blade.
- Titanium alloy. To produce this alloy, a titanium powder matrix and carbide inserts are sintered. For the longest possible period of time, it does not require sharpening, but such knives require careful use, which requires special skills in work and the availability of professional sharpening equipment.
- Zirconium alloy. It is a product made of hard mineral ceramics, which was subjected to dry pressing and firing. subjected to dry pressing and firing. They are sharp blades that do not dull for quite a long time, but their disadvantage is increased fragility and the need for special care and storage. Used for cutting soft products only. Sharpening is carried out using specialized tools.
To properly sharpen a knife, it is important to know what material was used to make it. The sharpening angle depends on these criteria. The harder the alloy, the smaller the angle should be. In addition, the hardness of the alloy is also affected by the method of sharpening the blade.
The design of modern combat knives
knives have become increasingly popular among sellers and consumers . A large number of experts in the field of old-school edged weapons believe that this term is not very correct and should not even be used. A tactical knife is a knife that can be used not only as a combat weapon, but also to perform household or household tasks.
Today, one of the trends in the development of combat knives has been the introduction into their design of the most successful technical solutions taken from the so-called survival knives. Another trend that is clearly visible is the maximum simplification of the knife design. In addition, a modern combat knife must be adapted to various conditions of use and be versatile. That is, to perform not only combat functions, but also to be suitable for various tactical actions, without which it is difficult for a fighter to do in combat conditions.
A combat knife must be able to quickly cut a cable or wire, remove branches or other obstacles, deal with a lock, dig a shelter, or open a can of canned food. The main challenge facing designers of combat knives today is the desire to combine the functions of a weapon and a tool in a knife.
Before starting the story about the most popular Russian and foreign combat knives, a few words should be said about the design of knives and the terminology that is used to describe them. And also say a few words about the most common blade shapes and sharpenings.
If we pick up any knife , we will see that it consists of two parts: a blade (1) and a handle (2). The blade ends with a tip (3), and the handle ends with a pommel (10). At the bottom of the blade there is a blade or cutting edge (4). On the side of the blade opposite to the blade there is a butt (6). A bevel, descent or grind is a surface that tapers towards the blade blade (5). Such a surface is called a false bevel if it does not end with a blade (for example, on the butt). It is designed to lighten the blade. For the same purpose, small grooves are made on the side surfaces of the blade - valleys (7). In addition, they improve the balance of the knife by moving its center of gravity closer to the handle.
Both fullers and false bevels are not very necessary for small and medium-sized knives; often the manufacturer makes them for aesthetic reasons.
The unsharpened part of the blade, located directly next to the handle, is called the heel of the blade (8). In this part the blade resembles an ordinary metal rectangle. The main part of the handle, by which the knife , is indicated by a handle; between it and the blade there is a cross (9), it is often (and incorrectly) called a guard. Previously, the guard served not only to protect the hand in a duel, but with its help it was possible to block the enemy’s weapon. However, today, even if a knife has a guard, it is of a decorative nature.
The part of the blade inside the handle is called the tang. There are several types of attachment of the handle to the shank. The back of the handle is called the pommel or head. Sometimes a hole is made in the head and a lanyard is inserted into it.
Blade shape
Knives are tools that combine two main elements - a blade and a handle. At the same time, the most important difference lies precisely in the design of the blades and the presence of components. The most important part that needs constant care and regular sharpening consists of:
- Cutting edge and its height.
- Butt and its thickness.
- Rectangular section and its height.
- Descents and their heights.
- Cutting edges, their heights.
- Thickness of cutting edges.
Most often, blades have the following blade shape:
1-5 - Wedge-shaped; 6 - Razor; 7 — Chisel (one-sided or Japanese); 8 — “Chopping Chinese”; 9 - Bullet-shaped.
Double-edged sharpening - on the verge of Russian law
Buying a knife is now very easy. Many stores and other retail outlets offer a variety of options for such products. But it should be remembered that the identification of a knife as a household item or bladed weapon very often determines the liability of its owner before the law. After all, household attribute (for example, some folding knives) can be easily carried with you, without any problems with law enforcement agencies, and a thing that falls under the definition of “cold weapon” when carried can cause unpleasant consequences - communication with the police and attraction to admin. responsibility.
At the same time, the official determination of the product for such weapons is carried out by the expert center of forensic science of the Ministry of Internal Affairs of Russia, after carrying out certain studies.
This structure is guided by the following operational indicators:
- constructive purpose for causing damage to “living” objects;
- a blade firmly connected to the handle (it must be motionless).
- There are also signs of products that cannot be classified as weapons. We list the main ones:
- lack of edge. It, for example, is replaced by a certain tool attribute (chisel, screwdriver, etc. products with a width of more than 3 millimeters) or rounded.
- small blade. It should be less than 9 cm.
- short handle. Its length must be no more than 7 centimeters.
- convergence of the butt and blade at an angle of more than seventy degrees;
- a handle that does not provide a strong hold when making an injection.
- weak blade, etc.
This is only part of the characteristics of household knife products. But it should be noted that a very important factor determining their compliance with the definition of “CW” is sharpening. If it is absent (the slopes are removed, but there is no cutting edge), the products are not recognized as weapons.
Another question is that double-edged sharpening is on the verge of Russian law. It has certain limitations. Only the so-called “one and a half sharpening” is allowed - it is allowed on two-thirds of the blade (we are talking about the butt side). This is the sharpening that a knife should have in order to be classified as a household item and not a combat item. If this factor is not observed, then for wearing such an attribute or violating the rules for storing it, they may be subject to administrative liability from 500 to 2 thousand rubles, with or without confiscation (compensated). Such a seizure means that the knife will be taken away and sold by the Ministry of Internal Affairs, and the proceeds (excluding costs) will be given to the owner (former) of such an item.
But in the case of the production and sale of knives with double-sided sharpening or other signs of military weapons, liability (criminal) is possible, which provides for corrective labor for up to 2 years, or imprisonment (that is, imprisonment) for the same time. (Articles 222 and 223 of Part 4 of the Criminal Code of the Russian Federation).
The process of sharpening and sharpening a blade
The process of dulling blades occurs due to:
- Friction of the blade against food when cutting.
- Rough contact of the blade with the surface of inhomogeneous particles, when the blade falls or hits other objects.
- Asymmetrical lateral loads.
- Chemical oxidation of the material when exposed to acidic foods and greens.
Dull blades can be identified quite simply - by eye or by touching with your finger. To correct a dull edge, sharpening is performed.
The main task of sharpening is to restore the correct contours on the cutting edge of the tool and polish it to the required degree of smoothness.
The main difficulty of sharpening for an inexperienced person is maintaining the desired blade angle during processing. To make this easier, the use of special devices and devices for sharpening knives is practiced. Not only kitchen appliances need sharpening; often at home, the edges of straight razors, hairdressing or household scissors, and other tools also need to be sharpened. Compliance with the rules and the availability of tools necessary for sharpening them meet the requirements for knives.
Most often, sharpening stones are used to sharpen all such types of tools. They may differ in shape and structure because they are made from different types of materials. These can be mineral natural stones, polymer alloys, abrasive mixtures or ceramics. In the process of sharpening a blade on such abrasives, it is possible to set the required sharpening angle, but such work requires special skills.
Any sharpener that is made on the principle of pulling the blades through does not allow you to set the sharpening angles, so it is suitable only for short-term editing. At the same time, for certain types of knives their use is undesirable, since it can lead to damage to the edge of the blade.
Often, for finishing or light sharpening, musats are used - such handles with a round rod on which longitudinal ribs are cut. But sharpening with musat requires some skill, so sharpening may not work the first time when using it.
It is also possible to use electric sharpeners, but they are not intended for a regular kitchen knife.
It is not recommended to wash the surface of knives, razors, scissors and other metal blades with hot water or wash them in dishwashers. Such actions will help prevent rapid dulling and will keep the knives sharp for a long time.
Before the process of sharpening knives yourself, it is recommended that you familiarize yourself with the training video presented or take master classes from knowledgeable craftsmen. Remember that a good knife is a true work of art.
Advantages of a serrated blade:
1. Increased cutting efficiency . The cut occurs simultaneously at different angles, which clearly increases efficiency when cutting layered and fibrous materials. Such materials include nets, ropes, belts, cables and the like.
2. Increased cutting edge length . With the same blade length, the total length of the cutting edge of a serrated blade is significantly longer, since the cutting edge runs along the curved line of all the teeth of the blade. If you calculate the length of all the bends of the serrator, then the working cutting edge will be longer than the blade itself.
3. Increased blade sharpness retention period . A partially dull blade with serrated sharpening retains its cutting properties longer compared to a conventional blade, since the load is distributed over a larger plane of the cutting edge, which means there is less load on each piece. Therefore, a blade with a wave-shaped sharpening does not bend and wrinkle as easily as a smooth blade. In addition, when cutting into the surface, large teeth press against the material with greater force than the smooth edge of the blade. The curved areas of the blade experience significantly less friction, so the blade stays sharp longer.
4. Ease of implementation into the material . What is meant here is that each tooth of the serrated blade penetrates the material almost like a prick, cutting the material around it on the sides, and with the same force on the blade, the cutting efficiency is much higher. The tip of each bend again and again cuts into the material and, as it were, tears it apart. The force applied in this case is concentrated at the edges of the wave bends, resulting in a greater depth of cut compared to the cut obtained from a blade with a smooth sharpening.
5. Increased effectiveness of a sharp, ripping blow, such as during a defensive action . With such a blade it is easier to cut clothing that protects the enemy’s body, given that the sharp serrator, clinging to the material with each tooth, will actually tear it apart along a directed line. A blade with a conventional sharpening, given the not particularly controlled defensive movement, can slide along the material and cut it only in the part where the maximum force was applied.
