NDK 17 saboteur knife, Kochergin design. NDK - sabotage knife poker

New addition to my collection! This time NDK! Kochergina Sabotage Knife or as it is also called Cardboard Knife :)

Once upon a time I saw this knife for the first time and since then it has sunk into my soul with its unusual shapes! And then the opportunity arose to fall on my tail and order from Elephants this wonderful Cardboard Knife made of high-tech steel whose name is Cronidur 30

This product was designed with a very specific target setting - a knife was needed that would meet all the requirements for weapons in the application system. hand-to-hand combat developed by the Center applied research"SPb.
In this regard, the developers were looking specifically for constructive ways to improve the cutting qualities of the knife and maximize the stopping effect when making an injection, since these requirements lay in the context of already existing and tested tactical and technical solutions for the weapon use system created by the Center.
It is deep cuts that best meet the tactical conditions of modern combat operations, when an injection is extremely difficult due to the widespread use of body armor and unloading, leaving only the face, neck and arms exposed.
Moreover, the injection is difficult to predict from the point of view results achieved, due to the lack of visual analysis of damage. A neck cut, as the main tactical task of using a knife, is very simple for analyzing and predicting the enemy’s further combat effectiveness. The guillotine type of blade replaced the narrow puncture wound, from dagger-type knives, to a wide frontal dissection with heavy blood loss.
The inclination of the blade relative to the handle is due to the constructive method of increasing pressure when the blade is pulled toward itself (when cutting). At the same time, the grip in the NDK 17 system is supported by the pommel of the handle in the palm. If you draw a line between the tip of the blade, the center of gravity and the point of emphasis, you will get a straight line that fully meets the condition of maintaining the straightness of the force vector during an injection, no matter how surprising it may seem given this form. Moreover, when testing the knife on a carcass, a frontal thrust cut 2 ribs on both sides of the target’s chest. This dissection is extremely difficult with other forms of the knife; moreover, getting stuck in the sternum and uncut bones is one of the problems of use combat knife, requiring subsequent extraction manipulations and special skills. Well, the most ingenious part of the whole project is the angle at the top of the blade.
This decision allows you to create, even with the knife moving straight towards you, an inclined cutting edge, which again has a guillotine nature of the cut.
Plus, this solution allows you to increase the force of pressure when cutting by an order of magnitude.

I’ll say right away that I’m still a self-defender :) I prefer to act as in that old saying “Better an old TT than Judo and Karate”, in general, for me it’s easier to shoot than to cut :) Therefore, the knife was bought more out of curiosity than for its intended use ! Well, like a cardboard knife, it really rules :) It’s very convenient to open boxes :) However, combat and everyday operations are usually rarely compatible! This is what happened here too. The fact is that for everyday life, a chisel sharpening with bevels on the left side will be somewhat inconvenient for a right-handed person :) But for a left-handed person, on the contrary, it’s just what you need :) I even thought it was a sin that they slipped me a knife for a left-handed person, but no, that turns out to be the author’s idea!
No, of course, it is quite possible to cut with it, but it will simply not be very convenient for a right-handed person and the pieces of cutting will not be uniform!

Well, one last photo for scale! I ask the experts not to laugh at the grip, the photo was taken just for scale :)

Well, about the elephants themselves! The locksmith makes me happy in principle! A solid four! But they screwed up with the pen! There's textured G-10 with quite sharp edges! And the rivets on the handle are sticking out! You can easily get yourself some calluses! Will have to work a little with a file :)
By the way, the one-sided (chisel) sharpening is very pleasing! Spicy as hell soton! At the same time, it’s quite easy to straighten, just scrape the block a couple of times and then remove the burr from the other side!

Target setting of knife design
This product was designed with a very specific target setting - a knife was needed that would meet all the requirements for weapons in the system of applied hand-to-hand combat developed by the Center for Applied Research in St. Petersburg.

In this regard, the developers were looking specifically for constructive ways to improve the cutting qualities of the knife and maximize the stopping effect when making an injection, since these requirements lay in the context of already existing and tested tactical and technical solutions for the weapon use system created by the Center.

Guillotine blade type

Moreover, the injection is difficult to predict from the point of view of the achieved results, due to the lack of visual analysis of the damage. A neck cut, as the main tactical task of using a knife, is very simple for analyzing and predicting the enemy’s further combat effectiveness. The guillotine type of blade replaced a narrow puncture wound from dagger-type knives with a wide frontal cut with heavy blood loss.

Blade tilt

relative to the handle is due to the constructive method of increasing pressure when the blade is pulled towards itself (when cutting). At the same time, the grip in the NDK 17 system is supported by the pommel of the handle in the palm. If you draw a line between the tip of the blade, the center of gravity and the point of emphasis, you will get a straight line that fully meets the condition of maintaining the straightness of the force vector during an injection, no matter how surprising it may seem given this form. Moreover, when testing the knife on a carcass, a frontal thrust cut 2 ribs on both sides of the target’s chest. This dissection is extremely difficult with other forms of the knife; moreover, getting stuck in the sternum and uncut bones is one of the problems with using a combat knife, requiring subsequent extraction manipulations and special skills. Well, the most ingenious part of the whole project is the angle at the top of the blade.

This solution allows you to create an inclined cutting edge, even with the knife moving straight towards you, which again has a guillotine nature of the cut.
Plus, this solution allows you to increase the force of pressure when cutting by an order of magnitude.
I can immediately say that I’m still a self-defender :) I prefer to act as in that old saying “Better an old TT than Judo and Karate”; in general, it’s easier for me to shoot than to cut :) Therefore, the knife was bought more out of curiosity than for its intended use! Well, like a cardboard knife, it really rules 🙂 It’s very convenient to open boxes 🙂 However, combat and domestic operations are usually rarely compatible! This is what happened here too. The fact is that for everyday life, a chisel sharpening with bevels on the left side will be somewhat inconvenient for a right-handed person :) But for a left-handed person, on the contrary, that’s what you need :) I even thought it was a sin that they slipped me a knife for a left-handed person, but no, that turns out to be the author’s idea!
No, of course, it is quite possible to cut with it, but it will simply not be very convenient for a right-handed person and the pieces of cutting will not be uniform!

Well, one last photo for scale! I ask the experts not to laugh at the grip, the photo was taken just for scale :)
Well, about the elephants themselves! The locksmith makes me happy in principle! A solid four! But they screwed up with the pen! There's textured G-10 with quite sharp edges! And the rivets on the handle are sticking out! You can easily get yourself some calluses! I'll have to work a little with a file :)
By the way, the one-sided (chisel) sharpening is very pleasing! Spicy as hell soton! At the same time, it is quite easy to correct, just scrape the block a couple of times and then remove the burr from the other side! Center for Applied Research

This knife was created for a very specific purpose - a product was needed that would meet all the requirements for edged weapons in the system of applied hand-to-hand combat created by the "Center for Applied Research" in St. Petersburg.

In this regard, the creators were looking specifically for constructive methods of increasing the cutting qualities of the knife and maximizing the stopping effect when making an injection, since these requirements lay at the basis of the already existing and tested tactical and technical solutions of the weapon use system created by the Center.

Design.

The point is that design modern knives to a greater extent is of a technological rather than a constructive nature. A vicious practice has developed when the shape of the blade may not be so much functional or practical in nature, but should catch the eye with the novelty of its lines and catchiness of presentation. For a combat knife, such strange target settings are in principle unacceptable. As a result, those currently in service in various armies, the knives are either modified copies of World War II scout knives, or variations on the theme of daggers. The HP and LDC available in our army today are, let’s say, just strong blades, and in the second case, they also shoot.

What exact requirements did the creators face when designing the NDK 17 knife?

1. Balancing the blade must have a center of gravity at the junction of the blade and the handle; this is a very important and absolutely necessary condition, which ensures high maneuverability of the blade during cuts and injections. So, if the center of gravity is placed on the blade, the knife receives advantages when chopping that are not typical for this type of weapon, losing the ability to quickly respond to hand movements and significantly loses in terms of pressure when cutting. This occurs due to the appearance of a significant shoulder in the lever, if we consider the upper edge of the handle as the point of application of forces. Thus, the number 17 present in the product designation means the primary length of the blade, approved in the name of the project, but reduced during testing to 150 mm, due to noticeably better maneuverability and balance.

2. The blade must have sufficient strength and high cutting qualities of the blade. This compromise is very difficult, since steels with high hardness and, as a result, high cutting properties, are often susceptible to chipping without having sufficient wear resistance during use.

3. The handle must meet difficult operating conditions, allowing for a tight grip and positioning of the blade without the aid of visual control, relying only on kinesthetic analysis when holding. It is for this reason that a rectangular handle made of padded leather was chosen - a very good hygroscopic material. The final test when testing the handle was cuts of a pork carcass in conditions where the handle was doused fresh egg, analogous to sweat and blood. The handle, due to the specified shape, was clearly positioned in the grip, even when abruptly removed without subsequent inspection, and did not slip out during injections and cuts, despite significant losses in friction when processed with egg. The guard on the handle is practically absent and is rather of a technological nature related to the fastening of the handle. This is caused latest research CPI, which convincingly prove that by complicating the maneuver with a knife and not allowing the full length to be used for cuts cutting edge, the guard does not help the hand in grip and does not save the hand from cuts during a symmetrical fight with a knife, that is, it is rather decorative, and therefore contrived.

4. The sheath was, perhaps, one of the most difficult and time-consuming tasks facing the designers.

Judge for yourself - the knife should fit tightly on any type of equipment, not make sounds when running and jumping, and at the same time be easily and lightning quickly grabbed. The presented version of the scabbard is a convincing result, more than three years research.

5. There is no need to clarify that the coating of this type of knife must simply have masking properties and protect the blade from corrosion. During this part of the research, absolutely all available methods were tested and studied, both bluing and coating the blade and handle with protective compounds. Epoxy blackening has proven to be the simplest and most practical solution, widely used in weapons practice both in our country and by leading foreign manufacturers such as Cold Steel and Ka Bar.

6. Cutting edge. This is the most important part of the blade, its main working area. It is the design of the blade that allows you to determine the purpose and practical value of any knife. In this case, a chisel was chosen - one-sided sharpening and here's why. It is this method of sharpening that allows you to achieve a small sharpening angle with a fairly powerful blade, in our case the blade has a thickness of 4 mm, a small angle is achieved by a straight descent of a blade 10 mm wide, which is quite comparable to such a rather serious cutting tool like a shoe knife. At the same time, one-sided sharpening makes it easy to edit and sharpen the knife, even in field conditions and with “military qualification” of the user. Sharpening is carried out on one side - exactly two times less likely to cover the entire Republic of Kazakhstan. Editing is carried out both from the descent side and from the unsharpened side.

From which components does the cut add up? From the pressure force when the blade comes into contact with the target, and the friction force when the blade moves along the surface being cut. It was precisely the task of increasing the friction force that prompted the designers to apply repeating notches with technical diamond (from the unsharpened part of the blade), which can significantly increase the cutting properties of the blade without affecting, however noticeably, the speed and ease of movement of the blade along the surface being cut. The effectiveness of this solution has been proven experimentally on various cut materials, including textiles.

7. The shape of the NDK 17 product always causes bewilderment among outside experts, why is the blade tilted relative to the handle, why is this angle at the apex needed, what is the use of a guillotine-type blade based on? This is what comes to mind for any traditional expert. And we would completely share their doubts if we first made, as often happens, an abstruse knife, and then were tormented in confusion about what to do with it effectively. NDK 17 was created for a complete and today one of the most laconic and effective systems for using a knife in the world, which eventually received the name of this knife itself - “the system for using a combat knife NDK 17.”

The creators were not looking for provocative, spectacular forms, but for weapons that maximally realized the very concept of this system:
-The predominance of cutting techniques over injections.
-Tactical task for the stopping effect of use, and not for the effect of a guaranteed and far from instant kill, as in the case of the use of stiletto types of weapons.

The inclination of the blade relative to the handle is due to the constructive method of increasing pressure when the blade is pulled toward itself (when cutting). At the same time, the grip in the NDK 17 system is supported by the pommel of the handle in the palm. If you draw a line between the tip of the blade, the center of gravity and the point of emphasis, you will get a straight line that fully meets the conditions for maintaining the straightness of the force vector during an injection, no matter how surprising it may seem given this form. Moreover, during the test of the knife on the carcass, 2 ribs on both sides of the target’s chest were cut with a frontal thrust. This dissection is almost impossible with other forms of the knife; moreover, getting stuck in the sternum and uncut bones is one of the problems with using a combat knife, requiring subsequent extraction manipulations and special skills.

Well, the most ingenious part of the whole project is the angle at the top of the blade.
We have already briefly touched on the tilt of the blade relative to the centerline of the handle by 20 degrees. This solution allows you to create an inclined cutting edge, even with the knife moving straight towards you, which again has a guillotine nature of the cut.
But the apex angle is a completely different solution, allowing an order of magnitude increase in the force of pressure during a cut.
Well, a little background on the appearance of this solution.

Karambits are knives that have maximum cutting pressure due to the crescent shape of the blade. But they at least have two drawbacks.

Crescent shape virtually eliminates stabbing strikes
-The very form of karambit is difficult to produce and even more so to maintain.

For all knives, the upper third of the blade is used most effectively when cutting; this is caused primarily by tactical reasons; the creators “straightened the sickle” and got a completely technologically advanced blade with an angle. When cut, a pressure is created that is not commensurate with the pressure of the straight blades of traditional combat knives. So, when testing NDK 17, a cut cut 620 mm. the chest of the carcass, and the “trauma” was total in nature with a through dissection of the ribs and soft tissues. For example, one of the best combat knives in the world, Tai Pen, cut about 150 mm with a cut and then left not a deep superficial wound, and the powerful Chinook was unable to make a cut of more than 200 mm, and all blades except NDK 17 received damage to the cutting edge.

Characteristics

Manufacturer: Elephant
-Purpose: Exclusive knife
-Blade (steel grade): D90
-Total knife length: 265mm
-Blade length: 150mm
-Maximum blade width: 40 mm
-Butt thickness: 5 mm
-Handle (material): Micarta
-Weight: 305g
-Scabbard (material): plastic
-Country Russia

The crude fiber content, which has been used for a hundred years, has lost its significance as a negative characteristic of feed quality. The negative side of the crude fiber indicator is that with an increase in its level in the diet, there is a decrease in digestibility, and therefore the energy value of the feed. However, ruminants are able to digest large amounts of hemicelluloses and cellulose in feed. And their ability to digest raw fiber is limited by the size of the gastrointestinal tract and the lignin content of the diet. Thus, crude fiber provides only a rough indication of differences in feed digestibility.

The second serious problem is that during the chemical analysis of feed under the influence of acids and alkalis, part of the hemicelluloses, cellulose and lignin are dissolved and filtered and are taken into account in the calculation in the BEV. Thus, the true picture of carbohydrate content is distorted.

Research from the VIZH Physiology Laboratory has established that crude fiber in various feeds, feces and duodenal chyme includes from 83 to 96% cellulose, from 6 to 25% hemicelluloses and up to 33% lignin. During the determination of fiber, it was found that from 4 to 17% of cellulose, from 77 to 94% of hemicelluloses and from 68 to 100% of lignin of the dry matter of the sample are transferred to the BEV.

Studies have shown that the total content of hemicelluloses and cellulose in feed is 46-60%, which significantly exceeds the amount determined by crude fiber (28-35%).

Disadvantages in the determination method led to the development of new analysis systems, which was proposed in 1965 by Peter Van Soest. The method is based on dividing the feed into two fractions: soluble in a neutral detergent and representing the most digestible part of the feed, consisting of proteins, fats, carbohydrates; and insoluble in neutral detergent and representing the poorly digestible part of the feed cell walls, consisting of hemicelluloses cellulose and lignin, lignified nitrogen and insoluble ash. Subsequent exposure of the feed sample to an acidic detergent (based on a solution of acetyltrimethylammonium bromide) allows for the dissolution of 82 - 84% of hemicelluloses, and the addition of sulfuric acid removes cellulose from the residue.

Carbohydrate fractionation using the Van Soest method is schematically presented in Table 1

Table 1

Fractions of plant carbohydrates and their characteristics

Thus, neutral detergent fiber (NDF) is the sum of cell wall structural carbohydrates consisting of hemicelluloses, cellulose and lignin, and acid detergent fiber (ADF) is cellulose + lignin.

It should be noted that NDF is not part of crude fiber, just as crude fiber is not part of NDF. Determination of crude fiber according to Hennyberg and Stoman and neutral detergent according to Van Soest are completely independent methods for determining fiber.

NDC is an indicator that best differentiates structural from non-structural carbohydrates in plant feed. NDC includes greatest number chemical compounds compared to crude fiber.

Depending on the type of feed, the amount of NDC can vary within significant limits. Thus, analysis of feed using the in situ method showed that the NDC content in them ranges from 6% (corn gluten) to 92% (corn cobs) and the degree of digestion within 24 hours - from 14% (peanut husks) to 77 and 78% (beer grains and soybean meal). A high NDF content was noted in roughage - straw up to 84%; lower in juicy - fodder beets - 17%: concentrates - barley (grain) - 19%, and legumes - from 53 to 77%. Moreover, the NDA content in the leaf blade of the plant is higher than in the leaf sheath.

The amount of FDC in feed is lower than the amount of NDC, since the former does not contain hemicelluloses. So in lawn grass the level of CDK was 32%, wheat straw - 56%, fodder beet - 10%, meadow hay - 30%.

So for corn silage this equation looks like this:

CDF% = - 1.15+ 0.62 CDF

for grass forage:

CDK% = 6.89 + 0.50 NDC (

for legume forage:

CDK% = - 0.73 +0.82 NDC

The degree of degradability of NDC is regulated by similar factors affecting the breakdown of crude fiber. This indicator varies widely in different feeds. Using the in situ method, it was found that the degree of digestion (24 hours) of the NDC of peanut husks is 13.5%, and of brewer's grains and soybean meal - 76.6 and 78%, respectively.

A study of leguminous grasses (main vetch varieties) for degradation and rumen NDF revealed a correlation between the degradability of NDF and its content in feed (r = -0.829), as well as between the degradability of NDF and the content of FDC (r = -0.826).

The US National Research Committee (NRC) recommends that ruminant diets should contain 75% of the total fiber from bulk feeds. The remaining 25% can be replenished with the NDC of such feeds as soybean hulls, whole cotton seed, flaked corn, etc.

It should be noted that diets with a total NDF content lower than 25% and lower than 16% NDC in bulk feed reduces the amount of milk fat. In addition, cows fed corn in their diet, which accounts for 16-21% of NDF, had a higher percentage of milk fat than cows fed corn and wheat 1:1 or corn and whole cotton seed.

At the same time, there is evidence that feeding cows with soybean husks as a source of NDF of non-bulky feed and only 16% of NDF of bulk feed did not lead to health disorders, dry matter intake and milk production.

There is also evidence that there is no difference in the productivity and percentage of milk fat in crowns when fed corn silage with 25% or 29% NDF content of the dry matter of the diet. According to some authors, the level of NDC in the diet of cows from the 10th to the 26th week of lactation should be in the range of 25-31% of the dry matter of the feed.

As for the FDC, in experiments on bulls fed alfalfa, the minimum and maximum limits for this indicator in the diet were established at 224 and 470 g/kg of dry matter, respectively. And if the amount of NDF correlates with the consumption of dry matter of the feed, then the FDC correlates with its digestibility (r = -0.75). At the same time, this relationship is influenced by the growing season of the plant, its type and the composition of the diet.

Using the in situ method, it was established that the rate of breakdown of hay CDK in the rumen is lower in cows when they are given milky barley grain or fodder beans as concentrates than when fed lupine grain.

Research from the Laboratory of Physiology of Digestion of Farm Animals has established the following levels of NDC and FDC content in feed and biological media (Table 2)

Tanto Jutsu of the Koi no Takinobori Ryu style, these are full contact fights with a wooden Tanto and using the entire arsenal of the specified style of combat Karate. Fights take place in a kimano, without protection and with only two restrictions:
- you can’t stab Tanto in the head
— you cannot do penetrating painful techniques on the eyes and neck.
Due to this circumstance, the fight in this type of competition is the most realistic fight with training weapons. The doctor does not have the right to remove a fighter without the decision of the judge on the mat.
Scores are given without stopping the fight, for powerful, technically competent injections, cuts in defined by rules, lethal zones or for strikes and painful holds that led to a knock-out, knock-down or submission of the opponent.
If a knife is lost or one of the opponents does not want to use it, the fight (by an unarmed opponent) is conducted by any means accepted in Hokutoki (a variant of fighting without rules), but taking into account the prohibition on penetrating painful techniques.
The style of knife fighting, Tanto Jutsu Koi no Takinobori Ryu, is for Russia the first official style of sports fights with a knife, held in our country according to approved international rules since 1997.

In addition to Tanto Jutsu sports fights, a domestic system for using a combat knife has been developed on the basis of this style, - NDK 17. This applied system of combat training differs from sports fights in its tactical orientation, which avoids the very possibility of symmetrical contacts with a knife and professes technical brevity. The scientific team of the Center has developed and is implementing domestic training methods special units in terms of fire training, applied warfare, tactics and group interaction. The result of joint scientific work with the VIFK is the NDK 17 combat knife, recognized by leading domestic and foreign experts as one of the most notable modern developments in the field of edged weapons.

A. Kochergin
Technical Director of IUKKK, Sihan 5th dan.
Scientific director of the "Center for Applied Research" St. Petersburg.

This product was designed with a very specific target setting - a knife was needed that would meet all the requirements for weapons in the system of applied hand-to-hand combat developed by the Center for Applied Research in St. Petersburg.
In this regard, the developers were looking specifically for constructive ways to improve the cutting qualities of the knife and maximize the stopping effect when making an injection, since these requirements lay in the context of already existing and tested tactical and technical solutions for the weapon use system created by the Center.
A little preliminary analysis.

The fact is that the creation of modern knives is more of a technological rather than a constructive nature. A vicious practice has developed when the shape of the blade may not be so much functional or practical in nature, but should attract with the novelty of its lines and catchiness of presentation. For a combat knife, such strange target settings are generally not acceptable. As a result, the knives that are in service in various armies are either modified copies of scout knives from the Second World War, or, without further ado, variations on the theme of daggers. The HP and LDC available in our army today are, let’s say, just strong blades, and in the second case they also shoot, it’s not clear, however, why. Provided that reconnaissance units have more suitable means of fire and silent firing devices for these purposes.
What exactly were the requirements that the developers faced when designing the product? NDK 17?

Balancing the blade must have a center of gravity at the junction of the blade and the handle; this is an absolutely necessary condition for ensuring the maneuverability of the blade during cuts and injections. So, if the center of gravity is placed on the blade, the knife acquires advantages when chopping that are not typical for this type of weapon, losing the ability to quickly respond to hand movements and significantly loses pressure in the part when cutting. This occurs due to the appearance of a significant shoulder in the lever, if we consider the upper edge of the handle as the point of application of forces. Thus, the number 17 present in the product designation means the primary length of the blade, approved in the name of the project, but reduced during testing to 150 mm, due to noticeably better maneuverability and balance.
The blade must have sufficient strength and high cutting qualities of the blade. This compromise is extremely difficult, since steels, which have high hardness and, as a result, high cutting properties, are often susceptible to chipping without having sufficient wear resistance during use. Steel grade selected...
The handle must meet difficult operating conditions, allowing for a tight grip and positioning of the blade without visual control, relying only on kinesthetic analysis when holding. For this reason, a rectangular handle made of padded leather was chosen, an excellent hygroscopic material. The final test when testing the handle was cuts of a pork carcass in conditions where the handle was doused with fresh egg, an analogue of sweat and blood. The handle, due to the specified shape, was clearly positioned in the grip, even when abruptly removed without subsequent inspection, and did not slip out during injections and cuts, despite significant losses in friction when processed with egg. The guard on the handle is practically absent and is rather of a technological nature related to the fastening of the handle. This is caused by the latest research by the Center for Research, which convincingly proves that by complicating the maneuver with a knife and not allowing the full length of the cutting edge to be used when making cuts, the guard does not help the hand in grip and does not save the hand from cuts during a symmetrical fight using a knife, that is, it is rather decorative , which means a far-fetched character.
The sheath was, perhaps, one of the most difficult and time-consuming tasks facing the developers. Judge for yourself - the knife should fit tightly on any type of equipment, not make sounds when running and jumping, and at the same time be easily and quickly removed. The presented version of the scabbard is a convincing result of more than three years of research.
It is not necessary to clarify that the coating of this type of knife must have masking properties and protect the blade from corrosion. In the process of carrying out this part of the research, all available methods were tested and studied, both bluing and coating the blade and handle with protective compounds. Epoxy blackening has proven to be the simplest and most practical solution, widely used in weapons practice both in our country and by leading foreign manufacturers such as Cold Steel and Ka Bar.
Cutting edge. This is the most important part of the blade, its main working area. It is the design of the blade that allows you to determine the purpose and practical value of any knife. In this case, a chisel was chosen - one-sided sharpening and here's why. It is this method of sharpening that makes it possible to achieve a small sharpening angle with a fairly powerful blade; in our case, the blade has a thickness of 4 mm. The small angle is achieved by a straight blade with a width of 10 mm, which is quite comparable to such a serious cutting tool as a shoe knife. At the same time, one-sided sharpening makes it easy to edit and sharpen the knife, even in field conditions and with “military qualification” of the user. Sharpening is done on one side - exactly two times less likely to cover the entire Republic of Kazakhstan. Editing is done both from the descent side and from the unsharpened side.
What are the components of a cut? From the pressure force when the blade comes into contact with the target, and the friction force when the blade moves along the surface being cut. It was precisely the task of increasing the friction force that prompted the developers to apply repeating notches with technical diamond (from the unsharpened part of the blade), which can significantly increase the cutting properties of the blade without affecting, however noticeably, the speed and ease of movement of the blade along the surface being cut. The effectiveness of this solution has been proven experimentally on various cut materials, including textiles.
The shape of the NDK 17 product always causes bewilderment among outside experts: why is the blade tilted relative to the handle, why is this angle at the apex used, what is the justification for using a guillotine-type blade? This is what comes to mind for any traditionalist. And we would completely share their doubts if we first made, as often happens, an abstruse knife, and therefore would be tormented in confusion as to what we could do with it that would be spectacular. NDK 17 was developed as a complete and today one of the most concise and effective systems for using a knife in the world, which eventually received the name of this knife itself - “the system for using a combat knife NDK 17.” The developers were not looking for provocative forms, but for weapons that would maximally realize the very concept of this system:

The predominance of cutting techniques over injections.
The tactical task is for the stopping effect of use, and not for the effect of a guaranteed and far from instant kill, as in the case of using stiletto types of weapons.

It is deep cuts that best meet the tactical conditions of modern combat operations, when an injection is extremely difficult due to the widespread use of body armor and unloading, leaving only the face, neck and arms exposed.
Moreover, the injection is difficult to predict from the point of view of the achieved results, due to the lack of visual analysis of the damage. A neck cut, as the main tactical task of using a knife, is very simple for analyzing and predicting the enemy’s further combat effectiveness. The guillotine type of blade replaced a narrow puncture wound from dagger-type knives with a wide frontal cut with heavy blood loss, which, in fact, is comparable to replacing small-caliber army pistols and supersonic ammunition with pistols using 9, and sometimes 11 mm calibers. having a pronounced stopping effect. The inclination of the blade relative to the handle is due to the constructive method of increasing pressure when the blade is pulled toward itself (when cutting). At the same time, the grip in the NDK 17 system is supported by the pommel of the handle in the palm. If you draw a line between the tip of the blade, the center of gravity and the point of emphasis, you will get a straight line that fully meets the condition of maintaining the straightness of the force vector during an injection, no matter how surprising it may seem given this form. Moreover, when testing the knife on a carcass, a frontal thrust cut 2 ribs on both sides of the target’s chest. This dissection is extremely difficult with other forms of the knife; moreover, getting stuck in the sternum and uncut bones is one of the problems with using a combat knife, requiring subsequent extraction manipulations and special skills.

Work of NDK-17 on lamb carcass.

Well, the most ingenious part of the whole project is the angle at the top of the blade.
We have already briefly touched on the tilt of the blade relative to the centerline of the handle by 20 degrees. This solution allows you to create an inclined cutting edge, even with the knife moving straight towards you, which again has a guillotine nature of the cut.
But the angle at the apex is a completely different solution, which allows one to increase the force of pressure during a cut by an order of magnitude.
Well, a little background on the appearance of this solution.
— Karambits are knives that have maximum cutting pressure due to the sickle-shaped blade. But they have at least two drawbacks.

Crescent shape virtually eliminates stabbing strikes
The very form of karambit is difficult to produce and even more so to maintain.

For all knives, when cutting, the upper third of the blade is used most effectively; this is caused primarily by tactical reasons; the creators “straightened the sickle” and got a completely technologically advanced blade with an angle. When cut, a pressure is created that is not commensurate with the pressure of the straight blades of traditional combat knives. Yes when testing NDK 17, the cut cut 620 mm. the chest of the carcass, and the “trauma” was total in nature with a through dissection of the ribs and soft tissues. For example, one of the best combat knives in the world, Tai Pen, cut about 150mm with a cut and then left not a deep superficial wound, and the powerful Chinook was unable to make a cut of more than 200mm, and all blades except NDK 17 received damage to the cutting edge. Video recording of testing is available both on television and in the archives of the developers’ website.

We are extremely pleased that more than 7 years of work on the creation and testing of the NDK 17 product has ended with such significant results.
But we want to make a reservation right away, this knife is far from universal and was created specifically for the “NDK 17” knife application system, which implies, first of all, the study of this system. Otherwise, our knife will not fully reveal its capabilities to you.

Sincerely A. Kochergin- Scientific director of the Center for Applied Research in St. Petersburg.

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