Sharp knife. How to tell a sharp knife from a dull one? Optimal knife sharpness according to the Tojiro scale. What determines the so-called sharpness of a knife

Not sugar, hard, below average pleasure, painful, painful, unpleasant, little pleasure Dictionary of Russian synonyms. sharp knife adverb, number of synonyms: 7 painfully (44) ... Synonym dictionary

Foreigner: about extremely unpleasant, cutting, like a sharp knife Cf. Romanov, my election Dosel is like a knife... Gr. B. Tolstoy. Tsar Boris. 3. Wed. These words pierced like a knife into the noblewoman's heart. She hit the ground in despair. Gr. A. Tolstoy. Book. Silver. 6.… … Michelson's Big Explanatory Phraseological Dictionary

Knife sharp- to whom. Razg. Express. The same as Like (what) a knife in the heart to whom, for whom. [Arsinoe:] Do you know it's a sharp knife to me When I see her playing you! (V. Kurochkin. Misanthrope) ... Phraseological dictionary of the Russian literary language

Knife (sharp) foreigner. about extremely unpleasant, cutting like a sharp knife. Wed Romanov's election is mine Until now like a knife... Gr. A. Tolstoy. Tsar Boris. 3. Wed. These words pierced like a knife into the noblewoman's heart. She hit the ground in despair. Gr. BUT.… … Michelson's Big Explanatory Phraseological Dictionary (original spelling)

1. to whom. Razg. About something unpleasant, painful for someone. FSRYA, 284; BMS 1998, 407; SPS, 128. 2. who cares. Razg. Extremely unpleasant, painful, causes mental pain to smb. what l. F 1, 333; Glukhov 1988, 113 ... Big dictionary of Russian sayings

knife sharp- to whom; … Dictionary of many expressions

Knife sharp- something extremely unpleasant, painful. FSVChiE ... Terms of psychology

Sharp, sharp; sharp and (colloquial) sharp, sharp, sharp. 1. Having a thin blade, cutting well, honed. Sharp knife. The knife is very sharp. Sharp sword. "A small mouse, but a sharp tooth." Proverb. Sharp (adv.) to sharpen a knife. || Tapering towards… … Explanatory Dictionary of Ushakov

BUT; m. 1. A cutting tool consisting of a blade and a handle. Table-knife. Penknife. Stab. Cut, cut with a knife. Dull, sharp knife. Finnish knife (short with a wide blade, usually carried in a sheath). Prepare, put under the knife ... ... encyclopedic Dictionary

KNIFE, knife, husband. A cutting tool consisting of a blade and a handle. Table-knife. Penknife. || The cutting part of different tools. Knife in a meat grinder. ❖ To be at odds with someone (colloquial) to be at enmity. Under the knife (to die; colloquial) to die during ... ... Explanatory Dictionary of Ushakov

Books

• A sharp knife for a soft heart
• A sharp knife for a soft heart, Maria Rybakova. A poignant modern romance about the love of a Russian girl, Marina, and a Latin American, Ortiz. About love that is beyond human, because Ortis is a river. And only by the power of the heroine's love...

Have you sharpened your knife enough or not enough? How do you know if a knife is already sharp or still dull? And is there a certain degree of sharpening that will be universally good for any knife? Answers to these questions can only be obtained by understanding why the knife cuts well and what threatens too small a sharpening angle.

What determines the so-called sharpness of a knife

We call a knife sharp when it cuts through (or cuts through) some substance without much effort on our part. Of course, if it is designed to work with her at all. But why is this happening?

What usually gleams when the blade is viewed from the side, we call the cutting edge or, even more incorrectly, the blade. In fact, it is more correct to talk about carts. Leads are very narrow planes that converge at one point along the entire length of the blade and form the very edge that cuts. Yes, it cannot be argued that the edge is a completely “imaginary” line, like the horizon - even with good sharpening it will be a surface a few microns wide. The main thing is that it should be of the same thickness along the entire length of the blade: this indicates that the thickness of the supply is the same everywhere, which means that it will be easier and more convenient to cut with such a knife. For a good cut, compliance with these conditions will be enough. It is possible to understand whether there is an edge on the knife at all and what its condition is, with a visual assessment. It is necessary to place the knife with the edge against the light and look at it. A blunt edge will glare along the entire length, a damaged one - in several areas. The ideal will not be seen.

The trick is that the sharper the edge, the smaller its area and the less light it reflects. And the smaller the area of ​​\u200b\u200bthis “imaginary” line (respectively, the sharper the supply lines converge at a sharper angle), the easier it is to cut with a knife and the sharper we call it. True, not every angle is suitable for some types of work - more on this below, in an explanation of why a "too sharp" angle is also bad.

Table for determining the optimal sharpness of a knife according to the Tojiro scale

Here is a small but very handy plate for determining the sharpness of a knife on a seven-point scale. How does it work?

• The highest score is 7. If a knife of a certain category has the correct sharpening angle (that is, the angle at which the supplies converge), it receives 7 points on the Tojiro scale.
• If the angle deviates slightly from the norm up or down, he gets 6 points; deviates more - 5 points, etc.

A logical question is brewing: are there sharpened knives that are “too sharp”? Is a sharper angle so bad that he gets a lower score? In general, yes. Firstly, you will spend more time and effort on setting a sharper angle, and not very justified. Because, secondly, such an angle will be non-functional. For example, if a hunting knife has a sharpening corresponding to a razor, it will be able, as they say, to cut chips from a hair, but it will be unsuitable for its intended purpose. The hunter accidentally hits the edge of the bone, and its damage cannot be avoided, and it will become inconvenient to work with a nicked or chipped blade. This means that this is the same flaw as the blunt edge, which is why an overly thinly reduced hunting knife gets only a four on a seven-point scale.

Table notes

• Delicate instruments are understood as surgical and shaving accessories; under fillet knives - devices for cutting fresh meat or freshly caught fish; all other kitchen knives will be universal; the fourth category will include all knives for everyday life in extreme situations, including combat and tactical ones; knives for heavy work can be called kukri, machetes and other tools for chopping and planing wood, as well as cleavers for chopping frozen meat and fish.
• Before you begin to determine the degree of sharpening, you need to make sure that the cutting edge is only an "imaginary" line where the supplies converge, that is, it is not worn out to gouges and chips. If the leads are to be repaired and actually straightened out again, it makes no sense to determine the angle between them.
• Particularly "hardcore" tools can still have a convergence angle of more than forty degrees, but only in the case of working with very hard materials and with a sufficient mass of the blade itself.

Hint: to sharpen a knife with a symmetrical blade section under the desired degree and get a score of seven points, you should remember that the angle can be half and full. The half angle is where you hold the blade in relation to the whetstone; full (twice as large) will be the angle that the leads form.
For example, to get a 20-degree approach angle for a tactical knife with symmetrical sharpening, you need to set it twice on different sides at an angle of 10 degrees to the surface you are sharpening it on.

How do you determine the sharpness of a knife?

The edge of the blade was examined under a multiple magnification microscope. The latest scientific developments were presented at the international mechanical engineering forum.

Incredible invention

The thin blade thickness of the ultra-innovative tool was 10 -9 meters. The sharpest knife in the world was designed for cutting small parts for microelectronics. It looks like a needle, the material for which is tungsten.

However, tungsten filament can only cut soft materials. But scientists are working in this direction. The world's sharpest knife was made using a unique technology. Each element of the blade is made up of tungsten atoms that are filled with nitrogen.

The thickness of the bonding layer turned out to be equal to one atom. This results in an incredibly sharp blade. The execution of work on the production of tools is low-cost, but the laboriousness of the process does not allow the mass production of knives to be launched.

Does the invention have a future and what are its advantages?

The sharpest knife in the world has undoubted advantages:

• They can even cut through microorganisms for study.
• They can perform operations at the cellular level.

An indispensable tool in industry: in the production of medical devices, military technology, high-quality electronics. It is applicable wherever the highest cutting precision is required.

The trace from the knife is no more than 50 microns. With this tool, you can cut along the thinnest human hair. Manufacturers note the resistance of the invention to high temperatures. It can be used at 800 degrees Celsius.

Invention for everyday life?

Kramer Knives recently introduced the world's sharpest kitchen knife for sale. Incredibly thin blade thickness is achieved through a specially developed technology:

• They melt 6000 layers of steel from America, Japan and Germany.
• The knife is made at a temperature of 1300 degrees Celsius.
• There is a stage of incandescence in a saline solution.
• Hand forging of each product.

Became the best among analogues. The blade is sharpened so sharply that the cut layers of products are completely transparent. Professional chefs choose Kramer Knives to make working in the kitchen a pleasure.

When ordering, the cost of a knife varies from hundreds to several thousand dollars. During the manufacturing process, each product acquires a unique pattern on the blade.