Sharpening knives: recommendations from experts. Diamond Venevian stones - sharpening set Abrasive stones for sharpening knives

The knife accompanies the man with early childhood and to old age. Each of us knows that it is a blunt blade that cuts the hand most often. To do this, it is enough for the blade to slide off the surface.

In order to avoid this, as well as to make the cutting process quick and comfortable, the knives are sharpened. But for sharpening knives, there are many different devices and methods, it is worth considering them in more detail.

Sharpening: principle and options

Blade sharpening is the process of removing the edge along the entire length of the blade at a certain angle with an abrasive. The sharpening angle depends on the hardness of the steel and the tasks facing the blade. So for household kitchen and hunting knives, the sharpening angle is 30 ... 35 degrees, hunting knife with resistance to blunting, sharpened under 40 ... 45.

Somewhat apart are the blades, which require a special sharpness of the blade, usually these are chef's knives or knives for professional processing of products, in this case the sharpening angle is from 25 degrees.

Separately, it is worth considering the sharpening angles of the razor and surgical instruments, since they require the sharpness of the blade. For a dangerous razor, the sharpening angle is 14 ... 15, for surgical instrument from 12 to 25 degrees.

Sharpening of knives is carried out in two ways, manually using abrasive stones or special tools and mechanically using grinding machine with a rotating abrasive wheel.

The first option requires skill, but at the same time it is easier to learn and accessible to everyone. Abrasive stones are used for sharpening various types, common:

• Arkansas, known as novaculitis;
• Japanese water stones;
• diamond bars;
• ceramics.

Each type of stone has its own advantages and disadvantages. These stones will be discussed separately below. For quick sharpening of kitchen knives, knives with a fixed or variable attachment of abrasive planes are often used, sharpening in which is carried out by moving the blade between sharpening surfaces.

Mechanical sharpening on the machine is much simpler, less time consuming, but requires constant temperature control and compliance with safety regulations.

Important! When sharpening on a machine with electrocorundum abrasive, it is necessary to control the temperature of the blade metal; when overheated, the steel of the blade can change its physical properties.

The main types of grindstone

In the course of the evolution of mankind, materials of natural origin suitable for sharpening knives were determined, although at the beginning of civilization, even ordinary sandstone was trusted to sharpen blades.

Now the information on metal processing has been structured and stones with the best abrasive properties have been selected.

Invented and worked out methods of working with them. In addition, widespread synthetic materials often the best properties than natural counterparts.

Arkansas stones

Novacula is a sharpening stone for a razor. This is a dense siliceous rock of homogeneous quartz crystals. Mining is carried out in quarries, Arkansas stone bars have several degrees of graininess, they are distinguished by excellent abrasive ability, but at the same time, due to their dense structure, they require the use of oil for sharpening.

Sharpening "dry" will clog the pores of the stone with dust and metal, causing the stone to fail. The main disadvantage of these bars is the price and uneven production with improper sharpening of the blade.

Japanese water stones

A natural stone originally from Japan, it has a high sharpening ability, but at the same time it is quite difficult to use. Sharpening knives on it is almost a ritual. Unlike novaculite, this abrasive is softer.

Sharpening is done with water. The process itself is quite complicated and time consuming. Stones are produced with a grain size from 600 to 30,000 grit in the Japanese JIS classification, while 10,000 grit is enough for superfinishing the blade.

Therefore, 30,000 is already excessive grit for blades. domestic use. Before work, the bar itself must be soaked in a container of water, after impregnation, remove it and create a mud mass on its surface using Naguro, the second abrasive bar in the water stone set.

With the help of this suspension, sharpening is performed. The surface of the abrasive is quickly and unevenly developed, for this reason, it is required to periodically restore it with the help of special bars.

Synthetic stones

Diamond sharpening stones, synthetic materials - electrocorundum, chromium oxide or diamond grit on a silicate or ceramic binder. These stones have a uniform structure, different (depending on the bar) grain size and good operational characteristics.

The cost of such stones is usually low, the bars themselves are available. Sharpening can be done both “dry”, which is not recommended, or with the use of water or oil.

Ceramics

These materials are used for blade finishing, finishing or superfinishing. The grain size of these materials is small, but at the same time they are quite cheap and will allow you to smooth out scratches from a peeling abrasive or straighten a knife with a serrated sharpening.

The use of a liquid is essential, since the pores in fired ceramics clog very quickly, the surface becomes smooth.

Grinding stones of various shapes are widespread, from standard whetstones, which are best worked on a stable plane, to rod sharpening stones, with which the blade is corrected on the go.

One thing remains unchanged, no matter what kind of bar, and what kind of metal, but for high-quality sharpening, lubricants are always used: water or oil.

Sharpening rules

First you need to prepare everything necessary materials. A sharpening block, a container of water and a paper towel or a plain sheet of paper. A piece of rag will also come in handy.

Immediately you need to determine the angle of sharpening. For example, 35 degrees is the most optimal angle for a kitchen knife or 40 for a sharp hunting knife.

Inspect the stone, if it has a trough or a significant development, then it should be leveled, otherwise the sharpening will be uneven.

The leveling of the stone is done with another stone, some types of stones, such as Japanese stones, have special comb stones included to restore the surface.

The bar is installed on a flat, stable surface, a table is perfect. To minimize slip, a cloth or rubber is placed under it. You can fix it on the table and in another improvised way. The surface of the bar is wetted with water or machine oil.

The position of the blade is adjusted by improvised means, for example, by putting a paper clip on the back of the blade or placing a coin. If the owner of the knife has strong nerves and a sharp eye, then simply holding the knife in the desired position is enough.

The knife is placed at an angle of 40-45 degrees to the center line of the blade, sharpening is carried out by forward movements of the blade away from you. For high quality sharpening, it is worth doing it in two steps.

First time on a coarse-grained peeling stone. Then, on finishing, fine-grained. During sharpening, it is necessary to periodically wet the surface of the stone. The check after sharpening is carried out both visually, examining the edges of the blade to the light, the sharp part of the blade is uniform along the entire length, should not give glare.

You can also plan a sheet of paper on weight. A sharpened knife cuts smoothly, without hooks and paper tears. The cut of the sheet is even, without shaggyness and tears. If the edge of the paper is torn, the sharpening of the knife must be repeated.

Conclusion

There are many stones, but each of them has its own characteristics, and, like a knife, it is selected under the arm. Synthetic stones are budgetary in operation. They are inexpensive and widely distributed.

But at the same time, to achieve softness of sharpening, you can only use natural stone, which has its own characteristics. Japanese water stones are good in terms of quality. But their price is very high.

In addition, sharpening with such bars is long and inconvenient. In addition, it requires mood and skill. The same should be expected from Arkansas.

Hence the conclusion, each stone is suitable only for its owner, if in nature or to correct the kitchen in between the series and reading the newspaper, then it is better to take synthetics.

She will forgive small mistakes, and the quality of sharpening does not play a role here. But for the sharpness of a hunting or combat knife, before a long trip to nature, you should use natural stones.

After sharpening, the knife is sharp, with edges and shape close to ideal. If you give the knife a lot of time and warmth, it will definitely not let you down, at the right time.

Video

For those who are not in the subject, so that there are no misunderstandings, I will explain the terms used:

Blade- The part of the knife that is not the handle. Usually made of steel or ceramic.

Butt- the back side of the blade, opposite the cutting side.

Descent- a narrowing going from the butt to the cutting part. For knives with a wedge-shaped section, the entire blade is made in the form of a descent. But for many knives, for example, for the Finn, the descent occupies only the 3rd part of the width of the blade, while the rest remains a flat plate.

cutting edge(edge, RK) - the edge of the knife, which is used for cutting.

Approach (chamfer)- sharpening going from the descent to the cutting edge. Typically, the approach completes the slopes, making the knife finally sharp (theoretically, knives are possible where the slopes end with a cutting edge without an approach). Almost always, the approach has some angle to the descent. If the knife is not altered, but simply sharpened, then it is the supply that is processed.

Microlead (microbevel)- part of the supply closer to the cutting edge, sharpened, in relation to the rest of the supply, under more obtuse angle. Micro-leads are sometimes made deliberately, usually with a finer abrasive, to increase the durability of the edge (so-called step). But sometimes they are the inevitable result manual sharpening on a bar without rigid fixation, as a result of which the inlet is slightly rounded. Since, when finishing sharpening on thin bars, they try to keep the angle more carefully, after sharpening, the supply turns out to be a rough bar, gradually changing the angle and turning into a finer sharpening.

The presence of a micro-advance is not a necessary condition for good sharpness. Moreover, done incorrectly (usually due to the difficulty of controlling the angle) results in the knife becoming blunter than it was before the micro-advance was formed. The knife can cut well and for a long time. So, usually even an unsuccessful micro-advance does not spoil the sharpening. However, shaving starts worse, or stops shaving altogether.

Machine- usually an electric sharpening machine with a circle or tape. It is used in industry for the rapid formation of slopes (in the event that they are not obtained by forging) and a cutting edge. In everyday life, it can be used to quickly regrind a knife to a new angle and create new supplies. Some NOT craftsmen try to use the machine for other purposes and, instead of reworking or making a knife, they try to sharpen it. This leads to unnecessary removal of metal, as a result of which, after several such sharpenings, the knife is disfigured. At the same time, it is not possible to achieve good sharpness on the machine (unless, of course, you have a set of discs of the required grain size, which is never the case in reality). And, in fact, sharpening a knife on a machine, people simply make the knife unusable.

In addition, sharpening on the machine often leads to overheating of the metal, as a result of which the knife is quenched, becomes soft and quickly dulls, requiring frequent sharpening.

Lamellar broaching sharpener- plates of hard steel or ceramics directed towards each other, between which it is proposed to drive a knife, peeling off the plates. As a result of peeling, the edge of the knife becomes thinner, increasing sharpness. However, such a peeling destroys the structure of the metal on the knife, leaving deep grooves (when viewed under a microscope), and stretching the metal. As a result, the edge is not very stable, it quickly becomes dull, jammed, and crumbled. You have to sharpen often, spending extra time on it and killing the knife.

The longitudinal grooves left by the sharpener prepare the metal for a quick break.
As a result, the knife becomes dull quickly and requires new sharpening, and this increases wear and time costs.

Musat- similar to a round file. Metal pliers are designed to unfold the wrinkled edge on soft knives. It is impossible to sharpen a knife on a metal musat. For hard steel knives, metal musat is generally useless. Ceramic grinders are usually a round whetstone and allow you to both turn the edge and sharpen the knife. However, a good sharpening of a knife on them is an almost impossible task. Grinding stones can be attributed to musat square section, about a centimeter thick. It is inconvenient to sharpen on this hybrid, however, as on ceramic musate, you can expand the edge and sharpen the knife.

Since the edge can be turned not only with a metal rake, but also with the butt of another knife, and the rake is useless for hard steels, the practical value of musat tends to zero. To use musat or not is a matter of taste. But musat is convenient when there is no desire to wash the knife. You can’t fumble with a dirty knife on a grindstone - the stone will then have to be cleaned for a long time. And the musat is easily washed off. So, for butchers, when cutting carcasses, the presence of musat at hand will be convenient

There is a widespread misconception that musat is more careful with a knife than a grindstone, because it does not remove a lot of metal. But, firstly, it is not necessary to edit knives with trimming stones, and secondly, loosening the edge in different directions, musat does not make it stronger. So, with the ability to use stones, the choice and the opportunity to wash the knife, musat becomes superfluous.

Sharpening system- a system for manually sharpening a knife, which allows you to do this while maintaining a constant sharpening angle. In this system, a file or whetstone walks along a guide. As a result, unlike sharpening by hand on a stone, in which the hand inevitably changes the angle, making the approach rounded, in the sharpening system the angle is always the same. As a result, peeling off the excess surface is excluded and, firstly, productivity increases noticeably, and secondly, the result looks more accurate.

Abrasive- the working part of the main grinding tools (bars, discs, sandpaper, ceramic musat). It can be presented in the form of a powder, mixed with something in the form of a paste (for example, GOI paste), cemented into a bar with some kind of binder, pasted on paper (metal plate, fabric). Abrasives are also part of natural grindstones. For example, many types of shale are sharpened by containing quartz crystals. Depending on the type of abrasive (albor, diamond, boron carbide, silicon carbide, chromium oxide, aluminum oxide, quartz, etc.), and the size of the crystal (grain), the abrasive properties of the tool vary.

Sharpening of knives and other tools begins with a coarse abrasive, gradually moving to a finer one. I think doubling or tripling the grain size is optimal. For example, after 200 grit, switch to 400 grit, then to 800 grit, etc. Everyone will decide for himself which sizes to use (for example, 240 => 500 => 1000, and possibly continue 2000 => 4000, etc. d.). It depends on what size you want to finish sharpening and what kind of abrasive is available. I decided that enough sharpness to stop at was achieved with 800 grit. For kitchen knives that are constantly subjected to cruel tests, such as cutting on ceramic plates, there is no point in fiddling with finer sharpening, as you can spend a lot of time sharpening, then cut a tomato on a plate and end up with a knife blunted on a plate. So, for universal kitchen knives, I determined sufficient sharpness obtained on a stone of 800 grit. And the rest of the dimensions were determined from this representation, dividing (for preliminary sharpening) or multiplying (for finer finishing) the values ​​​​by 2 and choosing from the available assortment the values ​​\u200b\u200bthat are closest to those obtained by division. It is the size of the step that matters. For example, a one and a half step will take quite a long time to level the furrows left in the previous step, and then the same amount of time in the next step. Each one and a half step will take the same amount of time as each double step. The quality will not change. Only time will change. Moreover, there is a possibility of excess metal removal. If you take a step too large, for example, after 220 go to 800, the furrows from a rough bar will have to be leveled so thin for a very long time. As a result, to achieve the same quality, with a large difference in graininess in each step, the time costs will have to be increased.

If you want to do the job quickly without sacrificing quality, choose right tool, and regarding grit, select the correct abrasive pitch.

In other words, it's okay if, in the absence of an intermediate abrasive, you went from 180 Japanese grit to 800. It will just take a little longer to work, and the wear of the 800 stone will be a little more. But, on the contrary, by adding a lot of intermediate ones, for example, 240, 320, 400, 600, you will not only increase the time costs, but also, most likely, remove too much metal. In this example, it is better to insert 1 stone at 320 or 400 grit, although you can insert nothing, just slightly increasing the processing time.

In conclusion, about abrasives, I want to note that if you do not make knives yourself, but only sharpen existing ones, you need an abrasive coarser than 400 Japanese grit (European standard F280, grain 36 microns.), just in case. But for jobs that require an abrasive coarser than 400 grit, it is better to use not a bar, but an electric grinder. Thus, the bars usually sold for sharpening knives are just not suitable for it. They can only perform preparatory work before sharpening knives. And they are sold everywhere just because they are cheap. An ordinary buyer cannot be convinced that you need to buy a stone 5 or even 10 times more expensive. He would prefer to take a bar for a dollar and not delve into the intricacies of sharpening skills. Accordingly, there is no one to sell normal grindstones for, and therefore there is no need to put them on sale. In addition, for most sellers, whetstones are just a related product, in which they understand no better than ordinary buyers.

A rock(bar) - an abrasive connected by some cementing ligament. At home, you can get it by mixing cement with quartz sand. However, industrial stones are made from more sophisticated bonds and abrasives. For whetstone great importance has the link on which it is executed. For example, diamond bars are often made by electroplating a diamond on a metal plate. Such bars rip off metal very aggressively, as they have very sharp and very hard diamonds sticking out strongly. They are well suited for forming slopes on the plate in the process of turning it into a knife and for restoring a badly killed knife. They are also the only method of sharpening ceramic knives. However, under excessive pressure, diamonds can tear out of the bond, which leads to baldness of the bar and loss of its sharpening ability. In addition, diamonds cut deep grooves in the metal, which, if not aligned, will quickly dull.

Some abrasives are not very strong and quickly become blunt, rubbing against the metal that is sharpened on them. To prevent the stones from losing their abrasive ability, brittle abrasives are often kneaded in a soft bond, which gradually grinds away, allowing the worn abrasive to crumble and expose fresh, not yet worn abrasive. This is how, for example, Japanese synthetic water stones Naniwa Professional (formerly called Chaucer) are made. However, the disadvantage of these stones is their rapid development, leading to a thinning of the stone and the formation of pits on them, which do not allow normal sharpening. As a result, soft-bonded stones, although they retain their abrasive ability, need systematic leveling (on glass, another stone, or even on a road curb). It is good to sharpen very hard steels with such stones, since they will never become dull. Also, they will not lead to chipping of the edge, since under excessive pressure the bond of the bar is broken, and not the steel being sharpened.

Stronger abrasives are often fixed with a rigid bond. The most rigid is ceramic. There are 2 types of ceramic bond: ceramics and glass-ceramics (vacuum-dense ceramics). In ceramics, the bars are brought to a temperature where the clay begins to sinter. And they are called bars on a ceramic bond. Glass-ceramic is produced at much higher temperatures, at which the clay turns into glass, in a vacuum environment to remove bubbles. They are usually referred to not as vitrified bars, but as ceramic bars or superhard ceramics. Ceramic bars practically do not wear out, but their price is not small, and their range is not large, since not every abrasive can withstand the glass transition temperature of ceramics. At the moment, corundum (aluminum oxide) is used in ceramic bars, as it withstands the required temperatures. Therefore, bars are often called alumino-ceramics. Ruby (a kind of corundum), zircon, cubic zirconia, chromium sesquioxide, boron carbide, silicon carbide can also theoretically be used in glass-ceramic bars. The disadvantage of glass ceramics is its high hardness. From excessive pressure on glass-ceramic on the edge of a knife made of brittle steel, chips may appear. If you press too lightly, the speed drops.

Some bars are made using an organic binder (Venevsky Diamond Plant, Naniwa Super Stone and others).

How roughly or finely a grindstone will work is determined by the height that the top of the abrasive rises above the rest of the surface of the bar and the distance between the tops of adjacent abrasives. In synthetic (artificial) stones, this is almost always determined by the size of the abrasive grain filling it. However, in a number of cases, the grains coalesce and intertwine with each other (typical of quartzite), or fuse into each other (glass-ceramics), so that the distances and heights depend on the degree of intergrowth (fusion). In this case, they say that the stone sharpens not with grain, but with structure.

Suspension- gruel of abrasive and water (oil). Either induced from a powder (or nagura), or formed as a result of grinding a stone. The presence of slurry on the stone will usually speed up sharpening, but can make it rough when working on very thin stones. And the thickening of the suspension on thin stones leads to a relative blunting of the edge (relative to what could be obtained on a clean stone).

Nagura- volcanic tuff (natural nagura), containing abrasive grains and a very soft binder, comparable to the strength of chalk, as a result of which it is used as a suspension stone. Thanks to the nagura suspension, it is possible to increase the roughness and aggressiveness of a thin stone, or to increase the productivity of a stone with the same grain size as the nagura. Due to very high price nagura and the fact that it only slightly speeds up the process, only special connoisseurs use it outside of Japan.

Naguru can also be used to clean the bar from clogging or as an independent bar. But in the case of using nagura as an independent bar, its wear is very high. It's cheaper to buy new knives than to sharpen on a nagura.

Sludge- worn metal.

coolant(coolant) - There are 2 main types of coolant used in sharpening: oil and water. They are called lubricating-cooling, because in sharpening, drilling, cutting materials with machines such as an electric grinder, drill, grinder, mechsaw and others, local overheating occurs, leading not only to loss of material properties (hardened steel loses hardening), but also destruction of the material and tool (locally overheated glass bursts, diamond abrasives ignite when heated above 800 degrees). There is a need to cool the area of ​​contact between the tool and the surface being machined. Also, to reduce wear, there is a need to lubricate.

When sharpening without the use of machine tools, the cooling capacity of the coolant does not matter, since critical overheating without high speeds is unlikely. However, lubricity is still important.

Actually, the process of sharpening a knife

If you are making a new knife from a plate, grind it sequentially on 120 and 240 grit stones, creating descents on it and removing so much metal that in the end on each bar the end becomes twice as thin (of course, it’s easier to start on an electric grinder). After 240 stone, the end should have a thickness of the order of a millimeter. Then grind the resulting workpiece with sandpaper or thinner bars, thus obtaining a very dull knife.

On a very blunt knife or a knife with a damaged edge that needs to be corrected (if the edge is bent, it is advisable to straighten it with the butt of another knife or musat before sharpening so that it does not scratch the grindstone and does not break out), it is necessary to form a cutting edge with a stone of 240-400 grit, making a lead. In this case, a burr should appear on the edge. This burr will indicate that the edge is completely machined, and you can proceed to the next step.

Before moving on to a thinner stone, you need to remove the burr by moving the knife butt forward, as if you were cutting the razor on the skin, on a piece of wood or, in extreme cases, on the same stone without pressure (another way to remove the burr is to change the sides of the knife with each pass).

Starting at 400 grit, the burr must always be removed when moving to the next stone or when sharpening is completed.

By sharpening a knife on a 400 grit stone, you get a knife of medium dullness, which, nevertheless, can begin to shave uncertainly. You can stop at this, but the edge will not be stable and will quickly become dull. And the sharpness is not enough for delicate work. Therefore, I recommend switching to an 800 grit bar.

800 grit is a stone for sharpening a not very sharp knife. After receiving and deburring this stone, the result is a knife that shaves uncertainly and has a relatively resistant edge. For many kitchen knives, this is enough, because once they are cut on a plate, it will be dulled regardless of the edge hardness (the hardness of the plates is much higher than the hardness of steel). However, if the knife is used only for cutting on wooden boards, or it is a chisel that requires the highest sharpness and durability, you need to sharpen on a 1500 grit stone.

1500 grit is the limit for a classic European kitchen knife (but not for a chisel and planer blade). After removing the burr, the knife will shave well without scratching, chop tomatoes without crushing, and it will be good to keep sharp.

But if this is not enough, sharpen on a bar of 3000 grit and above. As a result, you can bring on the skin with GOI paste. But the skin should not hang freely. Due to its softness, it flexes under the edge. A hole is formed in the skin, giving the edge of the knife a large radius and, thereby, blunting it. Ideally, the skin should be firm and glued to wooden base so that you get a leather whetstone.

In other matters, after stones of 10,000 grit and above, a leather bar is not needed. But these stones must be perfectly polished. Due to the complexity of this task and the high cost of fine-grained stones, leather is preferred by many.

To sharpen quickly, you need to take the right bar. For example, a 60-grit diamond will give the plate the shape of a knife in a minute, while a fine-grained corundum block will not be able to do it in an hour. Therefore, it is very important to choose the right grit and aggressiveness for a particular task. You can accelerate the rough peeling of hard steels with a diamond. For mild steels by priority: corundum, boron carbide, silicon carbide. It is good to use a sharpening system. It will not only make the work more accurate, but also by eliminating the processing of unnecessary, will reduce time costs.

I do not recommend trying to get an invisible edge with a large abrasive. Especially the diamond. Coarse abrasive creates deep furrows. If these grooves remain after sharpening, the knife will cut perfectly, but also quickly become dull as the teeth formed by the grooves break out. Moreover, deep grooves can lead to cracks and chips.

In order not to remove excess metal from the knife, with abrasives from 200 grit and coarser, it is better not to make descents thinner than 1 millimeter at the end and not to grind the cutting edge if it does not require alteration.

With a 400 Japanese grit bar, you can bring the slopes to 0.8-0.4 millimeters and shape the cutting edge so that its end is not visible to the naked eye.

The edge is never perfect, consisting of a line one atom thick. There are thousands or even millions of atoms on the edge. They form a rounded edge. The smaller the radius of this rounding, the sharper knife. But the abrasive always pulls out metal particles when moving away from the edge and drives them inward when moving to the edge. The size of these particles is comparable to the grain size. As a result, if you go to the edge with a rough stone, it will leave teeth with relatively sharp tops and blunt bases. To increase the sharpness, you will first have to grind these teeth to the base, thereby reducing the knife in size. The thinner the abrasive, the thinner both the tops of the teeth and their bases will be. The smaller the edge radius and the sharper the knife. Therefore, in order not to reduce the size of the knife, you do not need to go to the edge with a rough stone. You need to go to the edge with bars that give an acceptable sharpness, those on which, in principle, you can finish sharpening (for example, a knife cuts quite well at 400 grit).

The knife will be easy to cut even at large sharpening angles, if finished on a very small stone. Due to the large angle, it will slightly jam (blunt) when colliding with solid particles, and due to the finish on a thin stone and the small size of the teeth, the teeth will break out less when cutting (dulling the knife). Thus, by setting the knife at a relatively obtuse angle, but fiddling with it on thin stones, you can get a knife that will cut frozen meat and fish bones without hemming and without losing sharpness, but at the same time, cut tomatoes well. For these operations, of course, it is better to have different knives. However, thin stones, by increasing the time spent on sharpening, not only increase the durability of the knife, compensating for the time spent, but also increase its versatility. Knives with an obtuse angle begin to cope with delicate tasks, and knives with acute angle less afraid of rough work.

When trying to increase edge durability, it is important not to overdo it. Our kitchens are dominated by mild stainless steel knives. For example, the widely used Tramontina knives with a wooden handle have a hardness of 52 HRC. When sharpening such a knife to 10 thousand grit, the edge becomes much thinner than a hair, thinner than any foil. With such a thickness and such soft steel, it bends and smoothes, almost from a breath of wind. If you cut with pressure, the knife will cut and shave well (until the edge is bent). But if you cut by pulling, because of the smoothness, it will slip (soap). And it turns out that the same knife, sharpened to 1500 grit, cut better by pulling due to the relatively large saw on the edge, which is more resistant to burnishing. And it takes a lot of time to grind up to 10,000 grits. And it is more difficult to control such a fine sharpening, because due to the microscopic dimensions, it is no longer clear to the eye or to the touch whether the edge is well machined with another abrasive. But it turns out that the time wasted in vain, and on initial stage knife cut better. Plus, you need to take into account the thread on the plates, which kills sharpening in one movement. So, in each specific case, you need to determine your reasonable limit, and not mindlessly sharpen up to 20 thousand grits with a $250 Suehiro Gokumyo GMN200 stone just because someone wrote so on some forum.

It is important that when sharpening on thin stones, in order to avoid metal wrapping on the edge and the formation of craters, the knife must be moved with the tip in the direction of travel, or at least with the tip in the direction of travel as well (that is, as a last resort, unless otherwise inconvenient to sharpen back and forth). On rough stones, it is also better to move the tip forward in order to quickly expose the middle (edge). However, after finishing sharpening on rough stones, it may be useful to make a few movements with the point from the direction of travel to break off microburrs.

Time costs

With the right selection of bars, sharpening even a heavily killed knife to razor sharpness, even without a sharpening system, will take only a few minutes.

Do not listen to people sharpening a powdered steel knife with a hardness almost like diamond on a Japanese water stone or Arkansas. Diamonds sharpen diamonds!

Do you want to spend a week sharpening?

Do you want to level the bars on glass with silicon carbide powder for several hours after that?

Do you want to spend several salaries on unproductive bars?

If yes, full speed ahead, natural stones, Japanese watermen... and be patient.

Other gurus offer to sharpen everything with Venevian diamonds on an organic bond. They can be understood: why, in our technological age, hold on to the technologies of the Stone Age? Down with natural stones, down with too troublesome Japanese watermen! A few minutes and the knife is sharper than a razor!

But expensive. And, in fact, the cutting ability and resistance to blunting of the knife will not be perfect.

For those who are not ready to spend half their salary on grinding stones, there is no less technological solution: diamonds on a galvanic bond for rough sharpening, electrocorundum, boron carbide and silicon carbide in the middle of the path (but finer-grained diamonds are also possible), allumoceramic or natural stones at the final stage.

That is, a combination of different types that are most suitable for specific operations.

The speed is about the same. The cost is much less. Instead of carbides, stones from various types of corundum can be used. A little slower work, a little more often to update stones, but very cheap! The main thing is the correct grain size, the correct step, and not to remove excess metal, not to try to get a finished edge on a bar that is too rough. As the end of the edge thins, move on to a thinner stone. You don’t have to remove the excess, you don’t have to spend extra time and grind the knife.

Division of whetstones by coolant type

Since there are 2 main types of coolant (oil and water), in addition to the type of bond, type of abrasive and origin (natural or synthetic), it is customary to divide whetstones into oil and water. Water bars do not need to be moistened with distilled water. Just as oil is filled with different additives for different purposes, so water can contain "additives". For sharpening, any not too dirty water from a tap or reservoir will do. To reduce its volatility from the surface of the bar (with manual sharpening) and increase the ability to keep the sludge afloat, glycerin can be added to it. To reduce the absorption of sludge, detergent can be added to the bar. These additives will not change the essence of the coolant: water with "additives" will remain water.

The same can be said about oil: diluted oil or oil with impurities does not change its essence. Moreover, the word "oil" in this case should be understood wider than the usual ideas about it. Firstly, oil consists of fatty acid esters and, for example, oleic acid, as if not an oil, is an excellent coolant, and secondly, instead of oil, you can use any oily or soapy liquid, be it kerosene, glycerin or, even detergent (for lack of a better one).

Of course, whetstones do not have to be used with exactly the type of coolant recommended by the manufacturer. But this will not do without negative consequences: Arkansas on the water will clog with sludge and stop sharpening, the Soviet silicon carbide block will be dirty with oil absorbed into it until the end of days. Therefore, it is better to use the bars as the doctor prescribed. And if this is done, features are revealed in the bars: water bars emit a suspension consisting of a freely rolling abrasive. This causes them to wear more (than when used with oil), but sharpen faster. On fine-grained stones, another feature appears: fine-grained oil stones give precise strokes, smoothing the metal around them and, thereby, creating a mirror effect. Unlike them, in waterstones, the formation of clear strokes and smoothing is prevented by a cushion of suspension, which, breaking the contact of the bar with the surface to be treated, leaves its own short strokes and a matte effect.

Eventually stones in water generally work faster, while stones in oil result in a faster surface with a high degree of reflection and a more aggressive cutting edge(due to sharper strokes on it, which is good for knives, but bad for razors). This ability is used by craftsmen: having worked with a knife on a water block with water, they finish it dry to obtain an average result between oil and water stones.

There are bars that are positioned as bars for dry operation. These include vacuum-tight ceramics and diamonds on an organic or galvanic bond, as well as Naniwa Super Stone. However, oil-only vacuum-tight ceramics can be kept from clogging with sludge, and electroplated diamond plates lose speed if the sludge is not washed out with water. As a result, diamonds and Naniwa Super Stone work better with water than dry, and should be classified as water bars, while vacuum-tight ceramics work better with oil, and should be classified as oil.

For conventional knives and knives made of steel subject to rust, it is better to use oil stones. For knives with Scandinavian slopes, when sharpening without a micro-supply, it is better to use water stones, since wide slopes float on oil, almost without touching the edge. If you have to use an oil stone on scandispos, instead of oil, it is better to use either a detergent solution, or a very liquid oil or kerasin. In general, aquatic kaini are more versatile. However, some steels can rust when sharpened for a long time.

Don't sharpen diamond bars on a galvanic bond soft steels. The diamonds will cut deeply into the steel and gradually break out of the bar. Diamond whetstones are designed for sharpening very hard steels that slide over ordinary bars without sharpening.

Do not sharpen very hard steels, such as chisels and quick cutters, with bars on hard bonds, such as vacuum-tight ceramics. The abrasive will gradually blunt, but the bar will not renew itself, so the bar will quickly lose its abrasive ability. Alumina-ceramic bars can serve without wearing out for a long time, provided that very hard steels are not sharpened on them, so as not to render them unusable. Vacuum-tight ceramic whetstones are very good for sharpening relatively soft stainless steels, with hardness up to 58 (you can sharpen and steel is a little harder, but the harder the steel, the more the bar will be smoothed out).

Japanese synthetic water stones and their soft bond counterparts are suitable for most steels. However, many of them wear out relatively quickly (although there are also bars on a relatively hard bond). This erasure causes a renewal of the abrasive. Instead of a dull one, a new, sharp abrasive appears on the surface. This is the reason for the versatility of these bars: they sharpen any steel, as they are constantly updated. Due to the rapid renewal, the stones do not get clogged. But grinding, they lose their shape, require alignment and are gradually consumed. Buying new stones to replace worn ones is somewhat expensive, and leveling those that have lost their shape is troublesome. But, worst of all, many of the branded Japanese stones are demanding on drying conditions and can crack when fast drying. Keeping them wet, as is customary to do with Russian stones, is also impossible for many, since the most expensive Japanese synthetic stones are made on a gradually sagging magnesian bond. That is, when buying a Japanese synthetic stone, you need to understand very well how to work with this particular stone, the methods of exploitation of which can be very different from the methods of exploitation of other stones (including stones of the same company, but of a different series). Particular care must be taken with the bars glued to the stand. Due to the difference in the degree of deformation during swelling and the difference in the rate of swelling-drying, the bars glued to the supports tend to burst.

There can be no consensus on Japanese water stones similar to Naniwa Professional (formerly Chaucer). On the one hand, they are universal and sharpen everything. On the other hand, they need to be wetted, but then dried very carefully so that they do not become limp and cracked. They are clearly not as good as they are expensive. Needless to say, if sandpaper pasted on a piece of moisture-resistant chipboard costs 4,500 yen! For rough work, they are often inferior in performance to non-wear and cheaper Venevian diamonds (and even more so, diamonds on a galvanic bond), and for fine work they are inferior in quality to good samples of natural stones.

But buying a Japanese is easier than a good one. a natural stone. Natural deposits are depleted, and Japanese synthetics are inexhaustible.

Natural stones have different properties, and general recommendation on them no. They are of 2 types: some, in fact, are petrified silt with an admixture of silicon dioxide. Where silicon dioxide is an abrasive and silt is a binder. These natural stones do not have fundamental differences from synthetic ones. Contrary to popular belief about the inapplicability of the concept of grit to natural stones, silicon dioxide works according to its grit, no matter how the stone was originally polished. Just keep in mind that the strength of silicon dioxide is much lower than that of synthetic abrasives, and it quickly grinds, giving a softer sanding. These stones work by releasing a suspension. Other stones, in particular, quartzites (black hard Arkansas and Arkansas translucent), are practically pure silicon dioxide, the crystals of which have grown together. Their granularity is determined not so much by the size of the crystals as by the degree of polishing of the stone.

Quartzites have unique properties. They are mounted not with glue, but with time. It will take millions of years to reproduce artificially.

As a result, each natural bar should have its own recommendations. But personally, I don't see the point in using natural stones below 1500 grit. Diamond, silicon carbide, aluminum oxide (corundum), and often boron carbide, work faster and are better for fast metal removal.

Venev diamond bars on an organic bond have proven to be wear-resistant and sharpening any steel. But I would not recommend sharpening soft steels with them, so as not to increase their wear (because diamonds there are no less sharp than diamonds on a galvanic bond, and also, bogged down in soft metal, can be torn out of the bond). In addition, manufacturers made a reservation that on fine abrasives, somewhere from 1 micron (about 10 thousand grit), the powder can clump uncontrollably, forming clots in the bar, leaving rough scratches on the treated surface. Thus, the question arises, will a 10,000th organic-bonded diamond bar give sufficient polishing cleanliness? And in general, is this disease not characteristic of other artificial bars? Will 10,000 grit synthetic stones give the clarity of a good natural stone? Judging by the fact that large inclusions are sometimes found even in expensive Japanese synthetic stones, manufacturers of artificial bars cannot completely get rid of this problem.

Summarizing the information on the bars, you can offer options:

1. Proper selection of natural stones;
2. a set of Japanese water stones;
3. Venev diamonds on an organic bond;
4. a combination of galvanized diamonds for hard steels and ceramics for the rest.

The options are listed in order of cost and the hassle of caring for the bars (the need to level and grind). Although, often, caring for water stones is more troublesome than natural ones. At the same time, Japanese water companies can be replaced with cheaper analogues and make the option the cheapest, but still very troublesome.

The speed of work on each of these options depends on the metal being processed, but in general, option 3 is the fastest, and option 4 is only slightly inferior to it in speed. However, after diamonds, even Veneva ones, it is better to finish with a less cruel abrasive. For example, having sharpened a knife with a hardness above 61 with a galvanized stone to 800-1500 grit, bring it to good resistance on 1500-3000 grit aluminum oxide (corundum) bars on a relatively soft bond. And then, for maximum durability, bring on a good natural stone 5000 grit and above. Thus, both the maximum speed and maximum quality, and very small price(price compared to sets either from pure Venevian organic bars, or from Japanese high-quality synthetics, or from natural stones). An attempt to reduce the cost of a set of stones even more will lead either to a loss of speed (sharpening only on cheap aluminum oxide bars), or to a loss of quality (sharpening only on electroplated diamonds), or to the loss of both at the same time.

On the other hand, for kitchen knives, speed is usually not important. And the quality does not matter if the knife is immediately thrown into the sink, where it will get dented by hitting other knives, forks and plates. And then cheap aluminum oxide bars are quite appropriate. And 1500 grit is overkill. Sharpening such knives with a stone thinner than 800 grit is a waste of time. Edge stability will still be compromised by careless handling. Only if the attitude to the knife is careful, does it make sense to fine-tune it.

You should not buy thin Venevian diamond bars with a low percentage of filling. Having done a budget option, managers of the Venev plant promote it, claiming that fine-grained bars with a low diamond content are not inferior to bars with 100% filling neither in speed nor in quality. However, due to the low density of diamonds, each individual diamond experiences more pressure during operation and cuts into the metal more strongly than with 100% filling, making the processing rougher. Thus, bars with 100% filling work more accurately. And if they seem too expensive, then it is better to think about electroplated diamonds or other abrasives.

To get a visual representation of the difference in filling, pinch 4 studs between your fingers to form a mini-comb and scratch your hand with it. It might even be enjoyable. Then try scratching with one nail. It probably won't be pleasant. This is the difference between 100% and 25% Venevian bars. 25% with bars you hurt the metal! Of course, diamonds do not stick out of the bar like nails, and the effect is not so terrible, but, nevertheless, a 100% bar sharpens faster and better.

Starting from 8 thousand grits, the bars do not sharpen as much as smooth the metal (but for this they must be well polished, otherwise they will work much rougher than their grit suggests). So if you don't need mirror surface, then you do not need high-grip bars. They won't sharpen. Their task is to even out the smallest irregularities that accelerate the blunting of the knife.

In addition to choosing the type of bar, it is of great importance proper grit selection. If the knife has stopped chopping tomatoes, but cuts them well, you need to start sharpening it with about 1500 grit. If the knife does not cut tomatoes well - 800 grit. If the knife cuts very badly - 400 grit and coarser. No need to start sharpening a slightly dull knife with a rough bar. So you will not achieve more sharpness or speed, but more wear on the knife. It is better to sharpen the steel a little longer with a thin bar than to sharpen the steel unnecessarily with a rough one. In addition, smoothing the furrows from a rough stone may take longer than sharpening directly on a fine one.

The hardness of the bond and the density of the content of abrasive particles is also of great importance. A solid bar does not lose particles and if the particles are cut off the tops, the abrasiveness is reduced. At rough stages, this negatively affects speed. But in the middle stages, especially at high particle density, it can be used to make a bar with a relatively coarse grain give a smoother surface. This is sometimes used to make Translucent or cermet give a fine razor finish. The same is often used by rubbing different sides of the stone on powders of different grain sizes in order to sharpen quickly on one side and finely finish on the other. But this feature should be taken into account when choosing stones. For example, after a hard stone at 800 grit, the knife will be sharper than after a soft one at 1500, although the strokes after 1500 will be thinner, and the surface finish and durability will be higher. In this regard, it is often said that one cannot compare the grit value of natural stone (usually having a high hardness and a quickly grindable, polishable abrasive) or glass-ceramic, with the grit value of synthetic stone. But this is a simplified approach that interferes with understanding the physics of the process. By and large, different stones cannot be compared in terms of grit value at all. A soft alumina stone will work in a completely different way than a hard diamond with the same grit. The hard silicon carbide stone will also give its character to the work. And on a soft silicon carbide stone, you get the 4th option. And all with the same grain size. Grit is only one of the guidelines for abrasive ability. Bond hardness is another benchmark. Soft stones with the same type of abrasive work faster, while hard stones give greater sharpness. Accordingly, for the initial stages, if the wear rate is not critical, soft stones are preferred. And for the finish, hard ones are better. For example, sharpening a razor to 3000 grit is good on soft ones, and then move on to hard ones. And a kitchen knife that you are not going to spend a lot of time on can be finished on a hard stone of 1000 grit. However, it can be sharper than 3000 grit on an expensive but softer Japanese water stone. That is, by choosing the right hardness, you can get an inexpensive sharpening set that gives the same sharpness as a large and expensive set of stones with an unsuccessfully selected hardness (but keep in mind that the hardness of the bond provokes clogging).

The density of the particles is almost always the better, the more. Only if you need to loosen the surface, low density becomes useful.

Quartz widely distributed in nature in the form of sand, sandstones, quartzites, etc. Possessing a relatively low abrasive ability and strength, it is practically not used in synthetic whetstones. Quartz is the abrasive used for grinding slates, which is petrified clay mixed with quartz dust (silicon dioxide). It does a good job with classic steels. But not effective for powder.

Corundum(Electrocorundum) due to the relatively low abrasiveness due to the rounded shape of the grain (partially compensated by alloying and, for example, chromium electrocorundum - technical ruby ​​- has sharper edges), does not very effectively remove hard metal when normal pressures. But, having high strength (for example, in relation to brittle silicon carbide), it retains its abrasive ability for a long time. When used on fine-grained, hard-bonded bars, they produce inexpensive wear-resistant bars. And when used on coarse-grained bars, it allows you to increase the speed of processing mild steels by increasing the pressure (for rough processing, an increase in pressure is acceptable, but silicon carbide would crumble, preventing an increase in speed). In general, corundum stones are the most unpretentious and are usually used for sharpening stainless steel knives.

Carborundum(in translation it can be referred to as "green carbon stone" or silicone carbide), having medium abrasiveness and low price, it is used in sandpaper and grinding powders, allowing you to quite effectively remove metal of various hardness and viscosity. However, it is afraid of pressure and collapses into small particles, losing the ability to quickly remove. Therefore, in rough operations, it is often replaced by cheaper corundum, which makes it possible to increase the processing speed by increasing the pressure. Due to the low deformation strength, it wears out quickly when machining tough steels. And, despite the general versatility of silicon carbide, it is more practical to use electrocorundum bars for sharpening stainless knives. However, the rapid wear of silicon carbide (as well as silicon dioxide) has a positive effect on fine-grained bars: grinding on a suspension obtained from the destruction of crystals gives a cleaner surface. Therefore, fine finishing and grinding, ceteris paribus, is best done not on aluminum oxide, but on silicon carbide or silicon dioxide - quartz.

Boron carbide according to the table has a fairly high abrasiveness. However, it should be borne in mind that this is an indicator of the amount of glass abraded when 1 gram of free-rolling abrasive is worn (in relation to the amount of glass erased by the same mass of diamonds). Since boron carbide is light, there will be one and a half times more abrasive particles in 1 gram than electrocorundum. Therefore, when comparing the speed of 2 bars the same size, one of which is boron carbide and the other aluminum oxide, the relative abrasion of a boron carbide bar should theoretically be one and a half times less than expected from the table. In addition, the ability to abrade a large amount of glass for boron carbide is determined not so much by its cutting ability as by its wear resistance, which is more than 2 times higher than the wear resistance of electrocorundum. Boron carbide does not wear out longer, due to which it surpasses electrocorundum in "relative abrasive ability". In fact, if we compare the wear time of abrasives and the result obtained, the speed of boron carbide will be lower than that of electrocorundum. This happens because when crushed, boron carbide does not give sharp edges. But it has high strength, keeping the specified abrasiveness for a long time. As a result, it is usually used not in bars, where it would surpass cheaper aluminum oxide only in wear resistance, but in the form of powders and pastes for finishing cutting tools made of superhard materials like tungsten carbide and titanium carbide alloys (where corundum and carborundum would quickly wear out). However, boron carbide can be used in bars for mild steels, which can be processed without dulling. Due to the high wear resistance of boron carbide, such bars are logical on a very hard bond. As a result of the hardness and grain and bond, very wear-resistant whetstones are obtained. But this creates the problem of clogging, since the layer clogged with sludge does not crumble itself. Accordingly, when using a boron carbide bar with a hard bond, care should be taken to prevent clogging, and if it occurs, refresh the bar by cleaning or peeling off the clogged layer. It is these difficulties and the limitation to mild steels that have led to the unpopularity of boron carbide bar. However, when other types of bars are available, hard bonded boron carbide bars can be used on milder steels to reduce overall bar wear and thus reduce the cost of sharpening in the long run. Moreover, due to the combination of high hardness and roundness, boron carbide removes metal ruffled by coarse abrasive well, leaving a smoothed surface. This allows you to start grinding immediately after roughing, reducing the time spent on sharpening and reducing the need for medium-grained stones.

Experience shows that boron carbide is effective on steels up to 55 HRC. That is, it works well on almost all cheap stainless knives, including the cheap Tramontina series. But on Tramontina Professional Master and more expensive Tramontina knives, its effectiveness drops noticeably. That is, depending on your knives, it can be either an eternal, indestructible bar, or a useless bar.

Diamond(mostly synthetic), having high hardness and strength, cuts metal like plasticine. Due to the high cost, to obtain a bar, it is usually applied to the plates with the thinnest layer. But from this layer, grains of diamonds are pulled out by viscous steels. Therefore, it is most advisable to use for processing very hard steels and ceramics, which are difficult to process with other abrasives.

Elbor(cubic boron nitride) is almost as hard as diamond. In addition, it has good chemical resistance and withstands higher temperatures than diamond, which allows it to be used for fast cutting and grinding, significantly increasing the processing speed on machine tools. At manual processing, where there is no high temperatures, no contact with aggressive media, has no special advantages over diamonds, and therefore, due to the cost exceeding the cost of synthetic diamonds and low abrasive ability, the use in whetstones is not economically justified.

Marking of Russian-made whetstones

A - electrocorundum

C - silicon carbide

V - ceramic bond

B - bakelite bond

I want to note that the manufacturers of Venevian diamond bars claim that a grain of 1 micrometer corresponds to 12-15 thousand Japanese grits. But it's not. 12-15 thousand grit is already a fraction of a micrometer. However, regarding the bars, the statement of the Venevian manufacturers can be true, since in the 1/0 bar the particle size is less than 1 micron, which means that the bar can really have 12-15 thousand grit.

I also want to note that the type of operations performed is indicated conditionally, since everyone determines for himself which grinding is fine for him and which is rough. In addition, by varying the type of abrasive, type of lubricant and pressure, it is possible to increase metal removal for fine-grained bars or achieve finer work from coarse-grained ones. So, the operations performed are indicated only for an approximate idea of ​​​​the purpose of the abrasive of a given grain size.

In all descriptions I use the Japanese system, since almost no one indicates the grain size in microns, and the Japanese system of grit is commensurate with the grains. That is, in a Japanese stone of 800 grit, the grain is 2 times finer than in a stone of 400 grit. And in the Russian F400 (corresponds to the Japanese 800 grit), the grain is 3 times finer than in the F220 (although the F value would suggest about a twofold difference). Thus, only in the Japanese system does the value correspond to the size (pun intended). For the European system, it would be more convenient to simply indicate the grain size in micrometers. Even more confusion in the European standard is made by sandpaper, which, unlike the bars, is marked as "P" and has its own grain size gradation that does not correspond to the gradation in the bars.

Approximate grits of the most recognized whetstones (Spyderco aluminum ceramics and natural Arkansas):

According to this chart, Spyderco's cermet set is a complete kit for sharpening not too dull knives to near razor sharpness. Unfortunately, Spyderco does not offer a rough option. Together with him, the kit would allow you to sharpen quickly and strongly dull knives. But, alas, they do not have the coarse option. But the Arkansas set is presented even redundantly complete for sharpening (some of the stones can be excluded). However, due to the fact that it is a natural stone, it can be inferior to alumino-ceramics in the speed of work. Thus, the price / quality ratio of Arkansas is not justified even in relation to the expensive Spyderco. The exceptions are Translucent stones, which, judging by the reviews, can be polished to 6000 grit and above, and Black Hard, which, thanks to the close intergrowth of crystals, sharpens to 8-10 thousand grit, and quite quickly. These stones are rightfully considered the best for sharpening knives before switching to leather with paste. In this segment, perhaps only Chinese ruby ​​ceramics can compete with Arkansas, which, judging by the reviews, can be polished to the same degree, obtaining more cheap analogue. Other fine-grained counterparts cannot compete either in speed or durability.

It is also clear that there is no point in buying Norton India and Norton Cystolon at the moment, since in any city it is easy to find the same rough stones 20 times cheaper. Probably there will be another level of quality. But for such rough work, quality does not matter. With such a striking difference in price, for such rough work, only price and ease of use matter. In the red and purple zones of the table, the quality of the stones can be ignored. The roughing on the Stayer bar is just as good as the roughing on the Norton Cystolon. However, as the grain decreases, the requirements for the quality of the stone begin to grow.

) In particular, GOST determines in which 4 sieves different sizes what percentage of the grains should settle. As a result, to determine the size, you can take the maximum possible size grains (but there are only a couple of percent of such large grains and they will give only a few scratches), the size of the middle of these 4 sieves, or the average size of the main fraction (but not the main one can be contained in enough in large numbers to determine the nature of the processing). In fact, none of the options exact definition. But even if all the grains were exactly the same size, the abrasiveness would depend on the abrasive substance, the type of binder, the cutting fluid (coolant), the hardness and viscosity of the material being processed (which does not directly apply to the abrasives themselves, but is closely related to the substance which the abrasive is made of). Equally important is the pressure. At high pressure, diamond cuts to the fullest possible depth, and silicon carbide simply crumbles. As a result, diamond stones work rougher than carborundum, faster on hard materials, but usually slower on sticky materials. So, even within the same size, the nature of the work of different bars is different. Add here different percentages in different sieves for different standards and we get the possibility of only an approximate comparison of standards.

) Naniwa Professional Stones are not available below 400 grit. Since it is believed that below 400 grit the quality of the stones is not important. And on this page it says that 400 grit is the roughest of the stones needed for sharpening. Rougher stones are needed either to change the sharpening angle, or to fix a chipped knife. That being said, this page states that 1500 grit is the upper limit for many uses and provides a sharper edge than most new knives out of the box.

About the same thing is said on the Suehiro website. Namely, that the main sharpening of kitchen knives is done on stones of 320-800 grit, and final fine-tuning is done at 1000-1500. Sharpening on finer-grained stones, according to Suehiro experts, is not required for kitchen knives.

As you can see, the opinion of Japanese experts does not completely coincide and, in part, is determined by the taste of specific people. But to summarize, their opinion converges on the fact that sharpening kitchen knives requires stones of 400-1500 grit. Rougher stones are needed if the knife has been severely damaged, and thinner stones are needed for specific purposes (for example, for carpentry tools).

Anyone who has ever tried to cook anything on their own knows how annoying dull knives can be. Preserving precious nerve cells is not difficult, you just need to get a good sharpening bar, for example, a diamond one. Our article will tell you how to choose it.

Diamond whetstones for knives - the subtleties of choice

Among all the abrasive materials used to sharpen kitchen (and not only) cutting tool, diamonds occupy a special place of honor. Due to their unique structure, they are very high level strength and hence long service life. At the same time, such a bar is almost not clogged with chips - to completely clean it, just rinse it under running water or wipe it with a cloth. Sharpening with diamond stones is suitable for knives made of almost any material, from the usual stainless steel to cutting-edge ceramics. Although the latter, of course, will have to tinker for a long time. When choosing a diamond sharpener, you should pay attention to:

1. dimensions. For ease of use, the length of the bar should be at least 3-5 cm longer than the length of the largest knife.
2. Grain. To determine the degree of abrasiveness of diamond bars for sharpening knives, marking will help, which for domestic products includes several numbers separated by a line. Ideally, the household should have several grindstones with different grits: for peeling works(160/125, 200/160, 250/200), semi-finish sharpening (100/80, 125/100) and finishing sharpening (40/28, 50/40, 63/50). But it is quite possible to get by with one double-sided bar, the sides of which have a different degree of abrasiveness. For foreign-made bars, the grain size is indicated by one number from 200 to 1200, equal to approximate number grains per inch of surface.

Now there is an increased interest in knives, and industry and trade are experiencing a real "knife boom". As a result, they are of no less interest. Moreover, they have several types: they are manufactured and used in different ways. This article is intended to answer the most common questions about what sharpening bars are and how they differ.

Types of bars

Along with time-tested sharpening stones, all kinds of artificial bars. In general, they can be divided into four types: natural, diamond, ceramic and artificial. Let's consider each of them separately.

Natural stones for sharpening knives

The most famous of natural stones are " Arkansas stone» (novaculitis) and Japanese water stone. Both that and the other modern industry has learned to do artificially, so they can be called natural only with a certain stretch. However, even industrially made, these bars are very expensive, and working with them requires special patience and skills. So, for example, a water stone should be soaked for a long time before work, and in the process of sharpening it should be constantly lubricated and washed off metal dust from the surface. In addition, these bars grind quickly and unevenly, and it is difficult to restore them. Meanwhile, they give the highest quality of sharpening and therefore are popular among professionals. A beginner is hardly worth acquiring or using such stones.

Diamond stones for sharpening knives

This is a very popular type of bar. They possess large quantity advantages and virtually no disadvantages. Available in a variety of sizes and grits, they are easy to find on the market. Diamond blades for sharpening knives are inexpensive, wear-resistant, and highly efficient. Indeed, it should be taken into account that high efficiency metal processing requires a certain amount of caution, since it is easy to spoil the edge of the blade with a diamond whetstone. This stone is probably the most the best choice for the beginner. Particularly good results can be achieved using a diamond stone together with a ceramic one (for finishing).

Ceramic whetstones for sharpening knives

Ceramic stones are the most modern type of grinding stones currently in use. They are made from a special ceramic powder and combine the advantages of natural and diamond stones. Their use allows you to achieve the same high quality sharpening as that of natural stones, but at the same time, “ceramics” practically do not wear out and do not change shape.

However, ceramic bars also have a serious drawback. Sharpening with their help is extremely slow and time consuming, and therefore they are used mainly for finishing after sharpening with other stones, such as diamond.

Abrasive artificial stones

This is usually electrocorundum or various carbides in soft binders. These bars for sharpening knives have been known to everyone since Soviet times and need no introduction. They choose metal well, but wear out quickly and are not suitable for filigree sharpening, but they are extremely cheap and affordable.

If there are knives in the house, then sooner or later they become dull, and they have to be sharpened. Despite the seeming simplicity of this procedure, sharpening knives, however, is a fairly difficult task. Proper sharpening of knives is not available to everyone. This equally applies to sharpening kitchen knives, and sharpening collectible knives made of expensive steel grades, and knives for any type of professional activity. Consider the question of how to sharpen knives correctly.

What materials are sharpening stones made of?

In this case, we are talking about stones for manual sharpening of knives. Such stones (they are also bars for sharpening knives) are of four types, depending on what materials they are made of:

• from ceramics;
• from diamond stones;
• from natural stones found in nature;
• from Japanese water stones.

Each of the listed bars has individual properties and characteristics.

Detailed characteristics of stones for manual sharpening of knives

Bars made from ceramic materials, are considered the most common and affordable. For the most part, it is these bars that are sold in all economic trading establishments. Such bars are divided into several subspecies. The most common bar type "boat". This is a very poor-quality bar: with its help, only rough sharpening or editing the sharpening angles of the knife blade is possible. Somewhat better are the bars, on one side of which there is a smooth surface, and on the other - a rough one.

As for diamond bars, professional sharpening of knives with their help is quite rare. Firstly, it is difficult to sharpen knives with diamond stones. Secondly, a blade sharpened with diamond bars becomes dull again very quickly. Thirdly, diamonds deeply scratch the cutting edge of the knife, and, in addition, destroy the blade itself, “eating” it.

It is best to sharpen knives with natural knife sharpening stones, as well as Japanese water stones. Most of them are brought from abroad, and they have a high price.

How to choose the right knife sharpener

When choosing a whetstone for sharpening a knife, there are several tricks. These tricks have been tested over the years and therefore should be taken into account. First of all, you need to pay attention to the size of the bar. Its length should be twice as long as the knife blade. If you plan to sharpen the knife with your own hands, you should also pay attention to what the surface of the bar is. It should be smooth and not have cracks or scratches.

To sharpen kitchen knives, a double-sided ceramic bar is enough. You can also purchase two or three bars with different grain sizes for this purpose. It is better if such bars were produced back in the era of the USSR. Soviet whetstones are considered the highest quality. Of course, they cannot be found in stores now, but they are still found in markets and flea markets.

All these tips are quite acceptable for sharpening kitchen knives. If we are talking about sharpening more serious knives (for example, hunting knives), then in this case, in addition to grindstones, the well-known GOI paste is also needed. After sharpening, it polishes the cutting edge of a sharpened knife.

Compliance with the rules for sharpening knives

To properly sharpen a knife, you need to know and strictly follow the rules for sharpening it:

• It is necessary to clearly maintain the angle of sharpening knives. A knife for some special application should have a sharpening angle of approximately twenty degrees. If this is a utility knife, then the sharpening angle can be greater (from 30 to 40 degrees). The sharpening angle largely depends on the quality of the steel of the knife blade. If the steel is of high quality, then sharpening can last a long time. Usually kitchen knives do not sharpen at a small angle, for them they try to withstand a larger angle;
• It is not necessary to press the knife with force during the sharpening process. Strength when sharpening does not matter, but the grindstone fails very quickly;
• Before you start sharpening the knife, you need to wash the bar with water diluted with any detergent;
• In the process of sharpening, the blade should slide along the bar, and not vice versa. Moreover, strictly from oneself, and not in the reverse order, and also not in the “back and forth” sequence. One side of the knife is sharpened until a so-called burr appears on the cutting edge. After he appeared, the second side of the blade is sharpened in exactly the same sequence;
• After sharpening the knife on a rough stone, it is recommended to complete the turning process on a fine-grained stone. The sharpening process in this case is the same.

If this is a kitchen knife, then after sharpening on a fine-grained stone, the process can be considered complete. If this is a more “serious” knife, then after a fine-grained stone, the blade will have to be polished on the skin, while using GOI paste.

Learn more about sharpening Japanese knives

Japanese knives are sharpened in a slightly different way. The fact is that the blade of Japanese knives has a slightly different design than most other knives. Japanese knives are sharpened on one side only. Thanks to this geometry, products cut with a Japanese knife cannot stick to the knife blade.

Otherwise, Japanese knives are sharpened like all others. First, there is a preliminary sharpening on a stone with a rough surface, after which the sharpening is completed with a fine-grained grindstone. Finally, the sharpened edge is polished.

What is a knife sharpening machine?

Many under the machine for sharpening knives mean all sorts of home-made grinding units. In fact, it is highly undesirable to sharpen knives with such sharpeners. In just a few sharpenings homemade device for sharpening knives can ruin any knife to such an extent that it can only be thrown away.

It is better to purchase a factory-made knife sharpener. With it, knives are sharpened quickly and reliably, to a razor-like state. In addition, with the help of such a device, you can easily make the desired sharpening angle. True, the factory tool for sharpening knives costs a lot, more than 7 thousand rubles.

Device for sharpening knives at home

However, a high-quality device with which knives are sharpened at home can also be made with your own hands. It's not that difficult. A drawing for such a device can be easily found on the Internet.

On the Internet, you can find instructions for making two homemade knife sharpeners. One device in its design resembles a branded Lanski sharpener. The other fixture bears a strong resemblance to the Edge Pro Apex. The first sharpener is easier to make than the second, but on the second model you can sharpen the knife faster and better.

Set for sharpening knives in the field

If someone needs to go hunting, or hiking, or geological exploration, or for some other need, then, of course, a complete set for sharpening knives in a backpack may not fit. However, a truncated knife sharpening kit is highly recommended to put in a backpack. A double-sided bar, a piece of leather for straightening a blade - this is a camping kit for sharpening knives.

Such a set in field conditions can be very useful. It is clear that you cannot sharpen a damask blade with such a set, but for a simpler blade, a camping set for sharpening knives will fit perfectly.

What mistakes can be made when sharpening knives

When sharpening knives, you can make a number of typical mistakes:

• It is impossible to fully sharpen a knife with just one stone. For proper sharpening, you need to use several stones with varying degrees of grit;
• The knife can not be sharpened without noticing small burrs on the cutting edge;
• It is impossible to fully sharpen a knife without first cleaning it from the remnants of dirt or grease;
• Another mistake is choosing the wrong sharpening angle. With a large sharpening angle with such a knife, it is very difficult to cut products in thin layers. With a large sharpening angle, the knife will soon become dull in the process of cutting hard products.

A fully-fledged knife can be sharpened only if all of the above simple rules are observed.