All about knives. Instructions for making a folding knife
barb 09-06-2007 01:11
IMHO Adjustment of an axis is only 5% of all work.
RIA 09-06-2007 09:33
SanDude 09-06-2007 10:34
Fitting an axle without a lathe looks crazy..
P-a-a-please!
No seriously, if you use the axle that is sold on knifekits(
DRPPK - Precision Pivot Assembly) it is possible without a lathe.
And what happens? If I don’t have a lathe, then I can’t even make a warehouse worker?
SiDiS 09-06-2007 14:45
quote: Originally posted by RIA:
Fitting an axle without a lathe looks crazy..
Disagree
enough drills
RIA 09-06-2007 15:14
SiDiS well uh .. I agree kanesh but ..
SiDiS 10-06-2007 01:05
By the way .. on folds with a liner, compression, axis and arch, a very precise adjustment of the axis to the hole and vice versa is not critical. Keep within the top ten - it's normal. On these locks, the gap on the axis and 0.2 - 0.3 mm in the open state is invisible because these locks work on the principle of gap sampling.
But on the back is a completely different picture. With a perfectly fitted lock, the gaps on the axes of rotation of the blade and back are very critical and ideally should fit into a maximum of 2-3 weave. A gap of ten on any of these elements will be expressed in 3-4 at the tip, and on both - 0.5 mm or more. This is not always felt, because the spring on the back is powerful.
SanDude 26-06-2007 10:47
I read on an American forum about how to make a hole in the blade so that it is perfectly even and that the diameter deviates by no more than 0.005mm
Here's what they advise:
In the process of work, check the diameter of the hole with trial high-precision cylinders with a step of 0.002mm (A set of such cylinders is about $200!)
SiDiS 26-06-2007 13:47
1. Drill the blade before hardening a little less and make a hole a little smaller than necessary.
2. After hardening, pass the carbide reamer.
this is quite enough, and will allow you to get an accuracy of up to 0.03 mm, depending on the allowance left
quote: Originally posted by SanDude:
3. Then finish with a cylindrical lapping tool.
this is for aesthetic toolmakers
quote: Originally posted by SanDude:
It is necessary to drill on a milling machine, since there is more lateral runout on a drilling machine.
The milling machine is stiffer, a priori. A normal drill has enough rigidity, especially for reaming. And the radial runout is they look bad at the machine
RIA 26-06-2007 23:01
quote: Originally posted by SanDude:
2. After hardening, pass the carbide reamer.
Eh .. They would still have some good ones .. and not expensive shobs ..
SanDude 03-07-2007 07:21
Spoke to Ralph Darel from www.knifekits.com He said that the best smooth running would come from a reamer after hardening. When hardening, he says, the geometry of the hole is always violated. With lapping, he uses 400 or even 600 grit diamond paste.
He uses a friction bearing only from stainless steel. Bronze is not recommended. Gaskets advises bronze and in no case not Teflon.
SiDiS 04-07-2007 12:42
quote: Originally posted by SanDude:
He uses a friction bearing only from stainless steel. Bronze is not recommended.
Strange opinion, IMHO. Bronze and impact holds well and pleases with a low coefficient of friction with steel ..
quote: Originally posted by SanDude:
Gaskets advises bronze and in no case not Teflon.
Puzzled "... not in any case ..."
SanDude 21-07-2007 13:17
And how do you adjust the bushing and spacer in thickness so that the ends remain parallel?
SiDiS 21-07-2007 14:09
Yes, a couple of acres in thickness in both directions will not spoil anything
And if you are interested in a method, then I measure the thickness of the blade along with the washers and cut the spacer to this size.
SanDude 21-07-2007 22:56
I have tubules instead of a spacer. They are quite difficult to fix because. they are very short 4 mm. Next time I will use a flat spacer.
The folding knife, as we know it now, appeared about three hundred years ago. It was then that a lock was invented that allows you to fix the blade in the open state. But in fact, the history of folding knives is much older.
A small digression into history
Folding knives have been known since ancient Rome. Then every self-respecting Roman had to carry a folding knife with him. This is due to the fact that it was considered good form to come to visit with your cutlery, namely, a folding knife was used for eating. It was also used as a "pocket" tool and, to some extent, a self-defense weapon. The design of these knives was extremely simple: the blade was attached to the handle on a hinge and either hid in the handle or was taken out of it with a simple twist. IN open position the blade was held solely due to the force of friction, and when cutting - by the emphasis of the shank on the handle. Of course, such a design was primitive and short-lived, knives often failed.
The prevalence of folding knives as in Ancient Rome, and in other countries in later times is also connected with the fact that the carrying of a large knife or dagger was punishable by law. At the same time, the folding knife was considered safe, non-threatening, and anyone could carry it. So, in the 16th century in Andalusia, in southern Spain, Navaja folding knives appeared and became very popular. This was due to the tightening of anti-weapon legislation, which forbade representatives of the "low class" from carrying full-fledged weapons.
Springs and locks as part of the design of the knife appeared at the end of the 18th century, in America, during the American War of Independence. The folding knife even became part of the field equipment of the continental militia. The knife was also popular among the settlers, who actively used it on the farm.
At the end of the 19th century, folding knives were adopted by the Swiss army. The knife was primarily supposed to serve the Schmidt-Rubin M1889 rifle, which required a screwdriver to disassemble, as well as open canned food and perform other household functions. Such "soldier's knives" were made by Karl Elsener's company, which later grew into the famous Victorinox.
now foldable pocket knives, which are also called folders, folders, are experiencing a truly "golden age", as their popularity is growing at a tremendous pace. After all, it is an assistant for all occasions, useful in the household and safe for storage.
The design of a modern folding knife
A folding knife differs from a fixed blade knife primarily in that it has a movable mechanism that connects the blade to the handle. But, as with any knife, the blade and handle remain the main structural elements.
The blade of a folding knife has the same basic elements and parameters as the blade of a fixed blade knife. We wrote about this earlier in an article on. However, it also has additional structural elements associated with the need to open the knife and fix the blade in the open position.
Devices for manual knife opening
Subdigital foramen- this is a hole on the blade, usually round or oval, located closer to the handle. With it, there is a quick and easy opening of the folding knife.
Stud on the blade- a special stop, for the installation of which a threaded hole is drilled in the blade. A screw is screwed into it. Basically, knives have a one-sided peg, it can be screwed to the desired side of the blade - under the right or left hand. There are models equipped with symmetrical pegs, they are located on both sides of the blade. This knife can be opened with either the right or left hand.
Washer- this is a peg that is located on the butt of the blade closer to the handle. It has a rounded or rectangular shape with rounded corners. The side surface of the washer is usually notched.
Flipper, or fin- a special protrusion on the blade. When the knife is folded, the flipper protrudes above the top of the handle. With pressure on the flipper, a partial opening of the knife occurs. Further opening occurs either by shaking, or with the help of the thumb, or, if available, due to the assist spring. The flipper also acts as a guard, preventing the palm from slipping onto the blade.
Wave- this is a hook on the butt, which, when the knife is taken out, clings to the edge of the pocket and thus the knife opens. Wave was invented by Ernest Emerson specifically for tactical knives, for which opening speed is an important parameter.
Notch on the blade- the oldest and proven method of discovery, which is now infrequent. It is mainly used in models that have several blades or additional tools. Both hands are required to open.
Sometimes manufacturers combine opening elements: for example, a wave with a sub-finger notch. Or a peg and flipper, like semi-automatic knives.
It is more convenient to open knives equipped with protruding elements - a peg, a washer, a flipper, but they reduce the effective length of the blade. In addition, any protruding element may interfere with the quick removal of the knife from the pocket.
Handle
If the main requirements for the handles of non-folding knives are convenience and reliability, then the requirements for the handles of folding knives are more stringent, since their functionality is wider. The handle of a folding knife is primarily a receptacle for the blade, it must also accommodate folding and locking mechanisms. Therefore, the structure of the handle is more complex, and the materials used are more durable.
The handle design of a typical folding knife looks like this. The basis for the handle of a folding knife is an internal load-bearing frame (frame). These are two metal plates, or liners (liner), placed parallel to each other and interconnected with screws or rivets. IN modern models screw connection is more commonly used. It allows you to avoid loosening of parts that may appear during the operation of the knife, regulates the softness of the blade and facilitates the process of disassembling the knife during preventive maintenance.
A lock for fixing the blade and an automatic knife opening mechanism (for automatic and semi-automatic knives) are mounted inside the frame. Between the liners there is a groove in which the blade is located. The presence of the groove provides a rear tab that forms the ridge of the handle. When we fold the knife, almost the entire blade goes into the gap between the plates.
From the outside, the liners are decorated with overlays, which can be made of both natural (wood, bone) and artificial (fiberglass, micarta, carbon) materials. The overlays may be absent, and then the frame plates play the role of the handle, which in this case are made thicker. The overlays serve not only to decorate the handle, but also improve the grip, prevent the knife from slipping in the hand and generally increase ease of use. The combination of the frame with overlays gives the structure the necessary rigidity and strength.
In the front part of the handle, an axis is mounted in the plates, around which the blade rotates when the knife is opened and closed. There is also a limiter for the rotation of the blade in the open state. There are also gaskets between the side plates and the blade inside the groove, which are usually made of bronze or copper in expensive knives, and Teflon in cheaper ones.
If we talk about the geometry of the handle, then in shape they can be concave, convex, rectangular, wedge-shaped, with or without notches for fingers. In section - rounded, oval, rectangular. The shape and section of the handle determine the convenience and safety of using the knife. Their role is similar to the handles of fixed blade knives, which we already wrote about in the article about the structure.
Security elements
Modern models of folding knives are equipped with fairly reliable blade locks. However, the possibility of accidentally folding the knife still exists. Spontaneous opening of the knife can lead to serious injury - the blade can plunge into the stomach or thigh, or injure the hand in the pocket. To prevent this from happening, many knives are additionally equipped with fuses. For knives with a lock on the butt, the fuses are placed in the cutout area of the locking lever. For knives equipped with a linear lock, they are located in front of the handle, under the thumb.
In semi-automatic and automatic knives, the fuse blocks the blade not only in the open, but also in the closed state. After all, the trigger mechanism can be put into action and accidentally, when the knife is folded in the pocket.
Knives, supplemented with clamps, are comparable in reliability to knives with a fixed blade.
Carrying clip
For convenient carrying of a knife in a pocket or on a belt, almost all folding knives are equipped with a special clip, or clip, which usually looks like a steel springy strip. It is very convenient if the clip is made adjustable - that is, it can be fixed on both sides of the handle, under the right or left hand - as you like. There are models in which you can change not only the side of the clip attachment, but also its location - at the base of the handle or at the end. Depending on this, the knife in the pocket will be oriented with the tip either down or up.
In most cases, the clamp is attached to the handle with screws. If necessary, it can be removed and carried in a knife sheath. There are clamps and non-removable ones, but such knives are quite rare.
Elements that expand percussion capabilities
Folding knife can be used without opening the blade. For example, for the purpose of self-defense, when the knife acts as a palm stick. In this case, the blow is applied by parts of the handle protruding from the fist. To increase the impact efficiency in tactical knives, the end of the handle can have a triangular shape or a special impact element in the form of a cylinder, cone, pyramid.
Additional elements
Folding knives can be equipped with additional elements that expand the functionality of the knife. It can be a can opener and a bottle opener, a corkscrew and an awl, pliers and a screwdriver. Their number can be from one to several dozen. Their number and configuration depend on the purpose of the knife. So, tourist knives, in addition to the main set of tools, can have a saw for wood, fishing knives - a sling cutter, and hunting knives are equipped with a hook for ripping the skin.
A good folding knife is a synthesis the latest technologies And modern materials. He must have not only optimal dimensions and weight, but also a reliable mechanism for opening and fixing the blade. The ease of use and the speed of opening the knife, which can be important, as well as its strength and durability depend on this. Types of locks and their device are discussed in.
A variety of types of knives does not dry out the topic of their manufacture on their own. The knife is an ideal assistant not only in household but also for hunting, fishing and other outdoor activities. Some people probably need a knife for tough self-defense. But it is better to still try to avoid using a knife as a weapon of self-defense. There are less dangerous to human life and more legal self-defense items, so to speak. But life is life and you never know when, how and with what it will have to be protected. Camping and hunting knives are convenient to carry in a sheath, but in urban conditions, a cleaver on a belt will look pretty wild and will naturally attract the close attention of law enforcement agencies. Therefore, there are folding knives that are convenient to carry in a trouser pocket. We are going to make this today.
Naturally, it will be much easier to buy a folding knife, but people come to this site who do not pursue simplicity, but try to do everything with their own hands. The article is introductory and is aimed at readers who already have an idea about the manufacture of knives, so the description is rather short; but from the photographs you can understand almost every step of the work.
To make a folding knife, we need a titanium plate, although you can use stainless steel or some other good steel. Naturally, it all starts with the manufacture of a template, the shape of which you then transfer to a steel strip.
To begin with, we will make the liners of the handle of the folding knife. We outline the shape of the liner on a titanium plate and cut it out using any tool available to you. Next, we do a rough processing of the liner, grinding off excess metal on emery and files. Making the second liner. To do this, we apply the finished liner to a strip of metal and drill through two holes. We cut the threads into them, fasten the liners with screws without a cap and cut out the second liner, using the first one as a template. Next, we process the paired liners on sandpaper and files, approaching as close as possible to the contour line of the liner.
It was the turn of the manufacture of the blade of the folding knife and the back of the handle. We act in exactly the same way: templates, transfer to a titanium strip, sawing and processing on emery.
We drill holes in the liners for attaching the back of the knife handle. We assemble the knife and look where there are inconsistencies, gaps. If necessary, we refine these places, with files, achieving the perfect combination of all parts of the folding knife.
We dress the second liner and drill additional holes for attaching the back of the knife. You can fasten the parts of the knife handle with the help of special screws, having previously cut the threads in the holes with a tap. The screws are convenient because, if necessary, the knife can be easily disassembled and any modification can be performed. We flare all the holes for the screws with a larger drill so that the screw head does not stick out above the surface of the liner.
Next, we cut out the two upper and two lower metal lining of the knife handle. Glue them to the liners with superglue. Now we drill holes for the screws through the liners into the metal lining. The holes in the overlays should not be through. Now we put the knife in a bath of acetone to dissolve the superglue.
We chamfer the blind holes of the metal lining of the folding knife and cut the threads into them. We fasten the lining to the liners with screws. We customize the lining, under the shape of the liners, grinding off excess metal on the emery.Next, we make the final grinding of the knife handle.
From the inside, on the front metal plates, we drill recesses under the axis of the blade with a drill sharpened at an obtuse angle. For the axis, we grind the support screws on lathe. We cut the thread with a die.In the back of the handle we cut out a conical ( dovetail) groove for the leaf spring.
All metal parts of the folding knife are hardened using a homemade forge or gas burner.We will make the middle part of the overlays from any available material: wood, bone, plastic, plexiglass, textolite, etc.
We cut and grind the plate, adjusting its shape. The work requires precision, so adjust the middle lining slowly and periodically trying it on. After that, we drill blind holes in the liners for attaching a wooden lining. And cut out L-shaped slots.
All that's left is the lock. We drill holes for the lock at each end of the liner. We connect them with a slit. Then we make a transverse cut and get an L-shaped slot, which forms a blocking plate. We harden it with a gas burner and bend it to the side by three, four millimeters.
We drill a hole in the corner of the lock plate and press a metal ball into it. The back of this locking ball is ground flush with the spring plane.We sharpen the axis screw, making it a rectangular shape. We mill the slot for the screw in the liner body.We sharpen the fin of the back of the knife handle on both sides. We grind the metal parts of the handles. We make bevels on the blade of a folding knife.
Collecting a knife. But the axis is put on a thin washer, a blade, another washer. Then the second liner is put on. We insert the middle pads, snapping them into the L-shaped holes. We tighten the screws with a flat special wrench.
Urbanization modern world led to an increase in the popularity of folding knives (colloquially - "folders" or "folders", from the English folder - a folded object). Such a knife is compact and convenient for a city dweller, attracts less attention, and usually its wearing is absolutely legal.
It can be used for a variety of operations - opening envelopes and cardboard boxes, opening plastic packaging, cutting adhesive tape, etc. In a critical situation, it can also be used as a personal defense weapon. There was even a special term for the knives of a city dweller - “everyday carrying knife” or an EDC knife (from the English abbreviation EDC - Every Day Carring).
The activity of human rights organizations in many countries of the world has led to the fact that folding knives have come to replace knives with a fixed blade in law enforcement agencies and even in special units operating in urban areas. These knives are called "tactical". Surpassing urban knives in strength and reliability, they are inferior to them in size and weight.
In addition to self-defense, they can be used for a variety of operations - breaking doors, breaking through office partitions and of course, cutting ropes, etc. These knives are often used as utility knives in army units, as well as camping or outdoor knives.
The main types of blade retainers
Achievements of modern metallurgy and inorganic chemistry, the introduction of new materials processing technologies make it possible to implement the most daring design ideas. The close interaction of knife masters with hand-to-hand combat experts allows you to create original models of tactical knives with enhanced combat qualities. As a result, new models of folding knives appear with an unusual blade shape, ergonomic handles, and additional design elements that increase the convenience and safety of using the knife.
Knives with increased cutting properties
There is no perfect knife. Certain design solutions and elements increase the performance of the knife for certain types of work. In addition, there are no identical people, they have different sizes hands, they may have a leading right or left hand. For those who are not experts in the field of bladed weapons, the variety of designs creates a certain difficulty in choosing a knife for their needs.
Folding knife design
Folding knives have a long history and have gone from primitive designs to high-tech products, the manufacture of which uses the most advanced technologies.
A typical folding knife is a blade with one-sided sharpening, mounted on the axis of the handle. When folded, the blade of the knife is hidden in the handle.
The main structural elements of a knife are the blade and the handle.
In the classic version, the rotation of the blade occurs in the plane of the handle. Much less common are knives in which the axis of rotation of the knife is perpendicular to the plane of the blade. These knives look very original, but in terms of reliability they are inferior to knives of a classic design. An exception to this rule is articulated knives with a transverse opening of the blade.
In most folding knives, when open, the blade is in line with the handle. Among folding knives designed for personal self-defense, you can find knives in which the blade can be fixed in an intermediate position - perpendicular to the handle. In this case, the knife turns into a knuckle-grip knife like the famous “push daggers” (push dagger), originating from the daggers of the hidden carrying card players of the Wild West. The advantage of such knives is a simplified technique of striking - a blow is similar to a punch.
STI even developed the Tai sabaki knife (from the name of the Japanese body reversal technique), in which the blade can be fixed in six positions, which allows you to expand the technical arsenal of striking.
STI knife with blade lock in several positions
According to the opening principle, knives can be divided into knives:
- with manual opening and closing of the blade;
- with semi-automatic and automatic blade opening;
- fully automatic.
In knives with semi-automatic opening, to bring the blade into working condition, it is enough to slightly move the knife blade, and then it is brought to working condition by a special spring.
Semi-automatic knives and automatic knife (right)
In knives with automatic opening, for this you only need to press a special button or a folding trigger guard on the handle. In knife literature, such knives are often referred to as "automatic" or "automatic knives", although this is not entirely true, since the reverse operation of folding the blade is performed manually in them. A classic example such knives is the "Italian stiletto" and its numerous clones.
Buttons for opening semi-automatic knives and Italian stiletto
In fully automatic knives, both opening and closing of the knife is automatic. Moreover, the blade extends from the handle along the longitudinal axis of the blade (frontal ejection of the blade), and in the closed position it is completely retracted into the handle. This allows the use of dagger-type blades with two-sided or one-and-a-half sharpening in such knives, but imposes restrictions on the width of the blade - it cannot be greater than the width of the handle.
The process of opening / closing the blade is controlled by a special slider on the handle. These knives usually have a characteristic blade play. Only the specialists of the Mikrotek company, known for the high quality of manufacturing knives, managed to create automatic knives that are practically devoid of this drawback. But the price to pay for this is their high price.
Microtek automatic knives
The legislation of many countries, including Russia, classifies automatic knives with a certain blade length as criminal, and their wearing in these countries is prohibited. These restrictions do not apply to semi-automatic knives.
In order to avoid the risk of injury if such knives are accidentally opened in a pocket, they often have a special safety catch.
The main advantage of automatic and semi-automatic knives is to quickly bring them into working condition with one hand. It has great importance in knife fighting, as well as for people who, as a result of their professional activities, can operate with only one hand.
The disadvantages of these knives include increased sensitivity to dirt due to the rather complex design of the opening mechanism, and therefore less reliability. Cleaning the mechanism is a rather complicated procedure, especially in fully automatic knives, where it can only be carried out by qualified personnel. Therefore, automatic and semi-automatic knives are not well suited for field conditions.
These shortcomings are devoid of knives in which the opening of the blade occurs due to its gravity ("inertial knives"). The most famous of them is the knife of the airborne units of the Wehrmacht, which is still produced in a modified version today. The knife is very reliable simple design and can be easily disassembled for routine cleaning.
Fixing the blade in the open position is provided by special structural elements - locks(in English literature - lock). This fixation of the blade ensures the safe use of the knife, especially in operations where its piercing effect is necessary.
On the first primitive folding knives, the latch-lock was a special protrusion on the butt of the knife like a straight razor. Currently, there are many varieties of these devices. However, only three types of locks are most widely used - back up (lock on the butt of the blade), liner lock (strip lock) and axis lock (axial lock), as well as their varieties. All of them allow you to create knives that can be opened with only one hand, and provide a fairly secure blade in the open position.
A kind of lock on the butt of the blade
The lock on the butt of the blade (back up lock) considered the most reliable. But knives with this type of latch are difficult to fold with one hand. In addition, there is a possibility of accidental folding of the blade when the handle is strongly compressed.
Knives that use the kind of back up lock that was originally used on Spanish Navaja knives are free from this drawback. A similar lock is used on the South African Okapi. In this latch-lock, the blade is locked in the open position by a protrusion of the butt, which enters the hole on the spring bar of the lock. To disengage the latch in them, just pull on the special ring. IN modern versions the ring is replaced by a more compact and convenient folding bracket - a lever.
Linear lock (liner lock) compared to the previous one, it allows you to close the knife with one hand (in fairness, it should be noted that due to the asymmetry of the design, this is not very convenient for people with a leading left hand). Experts believe that in terms of the reliability of fixing the blade, this lock is inferior to the lock on the butt of the blade - with a strong longitudinal load, the end of the locking strip can disengage from the heel of the blade.
Much less common is ring lock, which is used on the French Opinel knives, which have been produced since the end of the 19th century. This lock has a very simple design - a slotted ring. To unlock the blade, it is enough to turn the ring so that its slot is aligned with the line of the blade. The same type of lock is used on the original domestic knife "Fortel".
In addition to the classic ones, there is a very interesting type of hinge-frame type knives. In these knives, the main structural element are special frames or hinges, which at the same time ensure the fixation of the blade. These knives are different. high reliability locking the blade in the open position while the knife is held in the hand. They have a symmetrical shape, so they are equally convenient for both right-handers and left-handers.
Frame knives consist of two frames, the planes of rotation of which are mutually perpendicular. Among domestic knives, these include "Chizhik" by master Konstantin Sazhin and "Skat" by the company "NOKS".
Frame knives "Chizhik" and "Skat"
Of the hinged knives, the most famous is the Philippine balisong (butterfly knife) and its antipode, in which the plane of rotation of the blade is perpendicular to the longitudinal axis of the knife. The latter is, perhaps, the only knife with a transverse tear-off of the blade, which provides a very reliable fixation of the knife blade in the open state.
Among articulated knives, pantograph knives have the most complex design. Typical representatives are the German Paratrooper knife and the Power Glide knife from Smith & Wesson.
Knives with transverse rotation of the blade
The Paratrupper knife, patented in Germany in 1938, is sometimes erroneously called the knife of the Wehrmacht landing units. An indispensable condition for knives for paratroopers is the ability to open it with one hand, and it is impossible to open the Paratrooper with one hand. The reason for this misconception was the name of the knife, which translates as "parachutist". However, this name is not associated with the purpose of the knife, but with the fact that its opening resembles the opening of a parachute canopy. The unique feature of this knife is that the length of the blade when open exceeds the length of the handle.
The main disadvantage of hinged-frame knives is the impossibility of opening the knife with one hand and the complexity of the design. The only knife of this type devoid of these shortcomings is the famous Filipino balisong knife.
Articulated knives
In most folding knives, when folded, the blade is completely hidden in the handle of the knife. Only part of the butt protrudes from the handle (for this reason, double-sided sharpening of the blade is not used in folding knives). However, there are knives in which, when folded, the blade comes out of the handle - semi-folding knives. A classic example of such a knife is the daggers of Admiral D'Estaing. This design combines the advantages of large fixed blade knives with the small dimensions of folding knives. This design of knives in the last century was quite common on hunting and jaeger knives. It is with this knife that Kuzmich cuts pineapple from the garden in the popular comedy "Peculiarities of the National Hunt."
Semi-skewed knives
The disadvantage of these knives is the need to use a sheath to carry them. Knives are free from them, in which the blade is retracted into a special groove that extends from the handle when the blade is folded.
A Soviet knife designed by A.I. Shilin, deputy chief designer of the Kovrov Plant No. 2 named after A.I. K. O. Kirkizha (State Union Plant No. 2). The knife was developed as part of a competition to select a folding knife for officers Soviet army, which was held in 1944, and took second place in this competition. According to some reports, in 1945 a small trial series of these knives was made. However, for unknown reasons, the knife never entered service. The knife had a blade with double-edged sharpening. When folded, the blade was hidden in the handle for two-thirds of its length. To carry the knife, a wooden sheath was used, inside of which there were special hooks that automatically extended the blade to its full length when the knife was removed. In addition to the blade itself, the knife handle contained a standard set of tools needed in Everyday life- Awl, corkscrew, screwdriver, can opener and bottle opener.
Officer's knife designed by A.I. Shilin and its modern Chinese counterpart
The ideas laid down by Shilin in our time have been used by the Chinese in the development of a special knife that is in service with the Chinese police.
The blade is the main part of the knife. It is from him that the piercing and cutting properties of the knife depend. The main factors determining the operational characteristics of the blade are the material and technology of its manufacture, as well as its shape and section. The blades of modern folding knives are made of corrosion-resistant steels. On blades from well-known manufacturers, the steel grade is often stamped on the blade at the base of the handle. On cheap knives, you can often see the inscription on the blade - "stainless" or "rostfrei", which simply means "stainless steel". Currently, the knife industry uses several dozen different steel grades. Because in different countries Since there are different standards for the designation of steel grades, the same steel may have different designations. The most common steel grades used for the manufacture of folding knife blades are shown in the table.
For an inexperienced user, it is enough to take into account the fact that the more expensive the steel, the longer it keeps sharpening, but this increases the fragility of the cutting edge and makes it more difficult to straighten the knife at home. The quality of the blade is largely influenced by the technology of thermal hardening of steel used by the manufacturer. With proper heat treatment, even relatively cheap types of steel provide good cutting qualities of the knife, and vice versa, even expensive types of steel with flaws in heat treatment will not ensure good blade quality. It is with this that the high cost of folding knives of well-known manufacturers with modern equipment and carefully monitoring the quality of blade manufacturing.
The hardness of the cutting edge is expressed in Rockwell units. Typically, folding knife blades are hardened to 42–60 HRC units. The larger this number, the longer the knife keeps sharpening, but you have to pay for this with less resistance to shock loads and the complexity of sharpening the knife. And, conversely, at low HRC values, the cutting edge is more plastic, easily sharpened, but does not hold sharpening well. With an increase in hardness above 61 HRC, the blade of knives with a normal butt thickness becomes very brittle. The edge of blades tempered to 42 pts. and less, has low strength and is difficult to cut ordinary materials. This indicator is not given on the packaging of knives. Even when describing the model on the manufacturer's website, it is not always possible to see it. When using a knife, it is necessary to take into account the fact that the knife blade is very sensitive to temperature rise. That is why you should not stir up the coals of a fire with a knife or use an electric grinder for metalwork or carpentry tools to sharpen it.
The surface of the blade can be polished, matted, blued, chrome-plated or have a special protective coating.
Polishing increases the resistance of the blade to corrosion, but such a surface shines in the sun, which is not entirely acceptable in tactical knives. Matting increases the anti-reflective properties, but worsens the corrosion resistance of the knife.
When the blade is burnished, a thin layer of protective oxide film is created on its surface, while the blade acquires a dark color. In chromium plating, a thin layer of chromium is applied to the surface of the blade, which prevents corrosion of the blade, but not its cutting edge.
IN modern knives blade coating made of synthetic materials ( epoxy resins, Teflon), which provide high resistance to moisture or acid and alkaline environments. Since this coating prevents the blade from reflecting in the sun, it is often referred to as "anti-reflective" and is often used on tactical knives. The disadvantage of such coatings is low wear resistance and sensitivity to scratches.
Recently, with the reduction in the cost of industrial production of Damascus steel, more and more blades are made from it. Damascus steel is obtained by forge welding several layers of steel with different carbon contents. As a result, a beautiful pattern appears on the surface of the blade. Modern industrial production of Damascus steels allows you to pre-design the shape of this pattern ("mosaic Damascus").
The combination of low-carbon steel strips for ductility and high-carbon steel strips for hardness of the cutting edge makes it possible to create blades with excellent performance. In addition, the cutting edge of Damascus steel knives has micro-teeth, which increase the cutting ability of the knife.
Knives with blades made of Damascus steel look very impressive. However, it should be borne in mind that the risk of getting a defective Damascus steel blade is much higher than when purchasing a knife with a conventional steel blade. This is due to the rather complex manufacturing technology of such steel.
Doly, which are often referred to as bloodlines, are longitudinal grooves along the axis of the blade and serve to lighten the weight of the blade. At the same time, they increase the rigidity of the blade in the transverse direction. Sometimes they are through cutouts.
Ricasso- the unsharpened part of the blade at the handle serves for the convenience of sharpening the knife.
false blade came from combat knives with a fixed blade that has one and a half sharpening.
Folding knives use the most different forms blades. For ordinary household operations, knives with a straight blade or a blade converging to a point are preferred. The disadvantage of the classical form of the blade is its lower strength at the point, since the thickness of the blade gradually decreases towards the point. Blades in the form of "tanto" or "modified tanto" are free from this drawback.
At the beginning of this century, first on knives with a fixed blade, and then on folding knives, a special blade shape with a reinforced tip began to be used. At the end of the last - the beginning of this century, knives with a sickle-shaped blade, which is typical for Malaysian karambit knives, came into fashion. Such a blade does not cut, but rips open the surface of the target like a plow. Knives with such a blade are used for self-defense or for cutting car seat belts. Knives in which the blade is located at an angle to the handle serve the same purpose. This idea got its maximum development in STI pistol grip knives.
Flat wedge has high performance, combining the strength of the blade and a sharp blade. Due to the uniform distribution of force, it cuts soft materials of large thickness well. Disadvantages - the complexity of sharpening, does not cope well with cutting hard materials.
Chisel profile- Differs in manufacturability and ease of sharpening. It is widely used on Asian knife blades. It has excellent chopping properties, cuts thin materials well.
Flat wedge and its variety, the plano-concave wedge with a supply, is easy to manufacture, easy to straighten and sharpen, perfectly performs a shallow cut. Disadvantages - low mechanical strength, difficulties in cutting thick materials due to protruding side ribs.
wedge profile has excellent cutting properties. The disadvantage is the fragility of the cutting edge and the difficulty of sharpening (it is necessary to sharpen the entire plane of the blade). From this disadvantage, a wedge-shaped section with a supply is free.
Pentagonal profile combines manufacturability, strength, good cutting qualities, well corrected. Disadvantages - the difficulty of sharpening when restoring the cutting edge.
In addition to the blade, folding pocket knives can have additional auxiliary tools - an awl, a corkscrew, a can opener, a bottle opener. In the so-called "Swiss Army knives" (Swiss Armyknives), the number of such tools can reach several dozen. Such multifunctional knives are called "multi-tools". For self-defense, knives with two working blades are also produced, which allow you to hit the target with the forward and reverse stroke of the hand without changing the orientation of the knife or changing its grip.
Part of the blade of the blade can be sharpened in the form of a saw for cutting fibrous materials. In the knife literature, such sharpening is called "sereytor" or "sereytornoy" (from the English. Serrated"sawtooth"). In self-defense knives, sereytor sharpening facilitates cutting through the upper dense clothing and can be performed along the entire length of the blade. The tooth configuration of this mini-saw may vary from manufacturer to manufacturer. The presence of a sereytor makes it difficult to sharpen the blade at home; for this, you need to have a special tool and skills to work with it, or contact the appropriate specialist. 
The design of most modern folding knives allows you to open them with one hand, both right and left. To do this, there are special elements at the base of the blade - cylindrical pins, round or round dies. square shape or holes in the blade (hole round shape protected by a patent owned by the American company Spiderco, and other manufacturing companies are forced to use other forms of it). It is more convenient to open knives with protruding elements - pins or dies, but they reduce the effective length of the blade.
At the beginning of this century, knives appeared special device in the form of a hook on the butt, which provides automatic opening of the knife when it is pulled out of a trouser pocket. Owners of such knives should be aware that if the trousers are made of thin material, then after several cycles of pulling the knife, they are likely to be torn.
Much less common on modern knives is a special semicircular cutout on the blade. Most often it is used in models that have several working blades or tools, or in knives without blade fixation, which are well known to the older generation in Soviet times.
Another element that facilitates the opening of the knife is the flipper (from the English. flipper"fin") - a special ledge on the butt of the blade. To open a conventional knife, it is enough to move the blade slightly by pressing the flipper with your finger, and then, with an energetic swinging movement of the brush, bring the blade to its working position. In semi-automatic knives, there is no need for such a move; the blade is brought to the working position by a spring mechanism automatically.
In addition, the flipper plays the role of a kind of guard, preventing the hand from slipping onto the blade.
The most common grip on folding knives is the straight diagonal (fencing) grip. In this grip, the thumb is located on the butt of the blade. For more comfortable control of the knife, a special notch is made at the contact point of the thumb on the butt of the blade. The part of the handle adjacent to the blade may also have a notch.
handles
The handles of most modern knives have a package type-setting design, consisting of an internal frame (frame) in the form of metal strips - liners (liner) and overlays. Blade fixing elements, automatic opening mechanism (for semi-automatic and automatic knives) are mounted inside the frame.
Simple monolithic handles with a groove for the blade or handles made of a bent strip of steel are rare in modern knives, mainly in the French Opinel and African Duk-Duk. Previously, the parts of the handle were connected into a single whole using rivets. The axis of the blade was also riveted. In modern models, screw connections are usually used for this. The use of screw connections allows you to eliminate the loosening of parts that appear during the operation of the knife, adjust the “softness of the blade stroke”, and facilitate the disassembly of the knife for maintenance work. Most foreign folding knives use screws with a torx slot (torx). To work with such screws, a special tool is required - screwdrivers or socket wrenches with the appropriate head. Some companies include such keys with the knife, otherwise they have to be purchased separately.
The shape of the handle, its section, as well as the texture of the lining determine the convenience and safety of using the knife. The rectangular section of the knife is technologically advanced in production, but not convenient when working with a knife for a long time. The handle with a round section fits comfortably in the hand, but it does not allow you to determine the orientation of the knife by touch. Therefore, oval-shaped handles are most convenient. The rectangular shape is compact, but it does not provide protection against slipping of the hand onto the blade. The wedge shape of the handle better protects the hand when working with the tip of the knife, but when trying to pull out the knife stuck in dense material, the hand will slide off the handle. Small penknives often have this shape for small household work.
The concave shape of the handle provides a more secure grip, but is not entirely comfortable. The convex shape of the handle fits perfectly in the hand and is comfortable to work with. It is this shape of the handle that time-tested Finnish-type knives have.
Even more convenient is the handle of a convex-concave shape and a shape that is often used on tactical knives. Modern knives are increasingly using handles of a complex shape that takes into account the ergonomics of the hand. However, its configuration is calculated for a medium-sized arm, and a person with a large or, conversely, a small hand, will not be able to take full advantage of its advantages.
overlays
For their manufacture, materials of natural (wood, bone, horn) and artificial origin (metals, plastic) can be used. The main advantage of wooden overlays is their "warmth" and the beauty of natural material. In expensive handmade knives, exotic woods with a very beautiful texture can be used. The main disadvantage is poor wear and moisture resistance. multilayer lacquer coating in some way solves the problem, but it reduces the reliability of holding the knife in your hand. Another material natural origin is horn and bone. Handles made of these materials are well polished and look very nice. The disadvantage is that they can crack and scratch easily. Metal linings are highly durable, but in the cold season, knives with such handles are inconvenient to use. In addition, they are difficult to hold in a wet or sweaty hand, even if they have a notch. In modern knives, titanium alloys based on aluminum or titanium are used for their manufacture. Damascus steel can also be used in expensive designer knives.
Materials based on synthetic resins make it possible to imitate the structure of natural materials and at the same time avoid their inherent disadvantages, although they lose to them in terms of weight. One of the most popular materials of this type is one of the types of micarta textolite. Recently, overlays from various kinds plastics, such as ABC, Zitel, Kydex, etc. These materials are technological, moisture resistant, durable and resistant to external environment. They allow the production of rubbers of any shape with any texture pattern - from a simple roughness inherent in the rubber material itself, or a rectangular cut to specially designed surface types. So, in the knives of the "For those who serve" series, CRKT uses a special honeycomb structure that prevents the knife from slipping in the hand. For the same purpose, rubberized inserts or structural inserts such as sandpaper are used.
At the end of the handles of many models of folding knives there is a through round hole for attaching a lanyard or lanyard to it.
Security elements
Although modern designs of blade retainers are quite reliable, nevertheless, as noted above, there is a possibility of accidental folding of the blade. To prevent this, modern knives have special fuses. For knives with a lock on the butt, they are usually located in the cutout area of the locking lever. In linear lock models, they are located in front of the handle under the thumb. The addition of blade locks with guards practically transforms the knife from a folding knife into a fixed blade knife.
For the safe wearing of semi-automatic and automatic knives, the fuse must prevent the knife from opening in a pocket of clothing if the trigger mechanism is accidentally actuated. Therefore, in such knives, the safety often has a double action - it blocks the blade in the closed and open state.
Clip (clip) for wearing
An almost mandatory attribute of modern folding knives is a steel spring clip. In knife literature, the term “clip” is often used to designate it (from the English. clip clamp, clip). It provides convenient carrying of a knife in pockets of clothes or on a trouser belt.
Many knife manufacturers make the clip adjustable - that is, it can be fixed on different sides of the handle, depending on whether the owner is right-handed or left-handed. In addition, sometimes you can change not only the side of the clamp attachment - at the base or at the end. In this case, the knife in the pocket will be oriented either with the tip down or up. Some experts believe that when carrying a knife with the point up, there is a possibility of a cut when trying to get the knife out of the pocket, if for some reason the blade comes out of the handle. At the same time, with such an orientation of the knife, it is faster to bring it into working condition.
In some models of folding knives, the clip attachment point is not Z-shaped, but shaped like the letter "G" or "P". In this case, when carrying a knife in a pocket of clothing, the upper part of the handle is hidden from the outside eye - only the spring plate of the clip protrudes from the pocket. Outwardly, it looks like a regular ballpoint pen.
Elements that expand percussion capabilities
For self-defense, the knife can be used without opening the blade. In this case, it is used as a palm stick and the blow is delivered by parts of the handle protruding from the fist. In tactical and self-defense knives, the end of the handle to increase the effectiveness of such strikes often has a triangular shape or a special impact element in the form of a cylinder, cone or pyramid.
Concluding the review of folding knife designs, it should be noted that the legality of a knife, that is, the fact that it is not a cold weapon, can only be determined by an expert by law. Therefore, when purchasing a knife, it is always necessary to ask the seller for a copy of the information sheet for the certification test report (in common parlance it is often called a “certificate”). The absence of such a document, no matter what the seller says, may indicate that the knife you like has not passed the tests for belonging to melee weapons. Moreover, it is best if such tests were carried out by the parent organization "Expert Forensic Center of the Ministry of Internal Affairs." It is best to always have a copy of this document with you, which will allow you to avoid unnecessary conflicts with law enforcement officials. 
Most high-quality folding knives on the Russian knife market are the products of foreign companies. Unfortunately, the majority of serial domestic folding knives are inferior to foreign ones in almost all respects, and you can rarely find original models among them. Russian craftsmen and knife companies prefer to create knives with a fixed blade, and among them there are very original models that have no analogues abroad, which include Vitaly Kim's knives, the Kondrat knife, the NDK-17 knife (saboteur knife designed by Kochergin) . This is largely due to the more complex technology and the expensive equipment required for it. Among Russian craftsmen, only a few design and produce original folding knives of the author's work that are not inferior to foreign ones (including in terms of price). Folding knives of the Ural master Urakov and the workshop of the Shirogorov brothers are shown as an example. The rapid pace of development of the Russian knife industry allows us to hope for the appearance of domestic folding knives that are not inferior to foreign models.
Anatoly Fomin. Magazine "Bratishka" 2013-01
In the most simple models the blade does not lock in the open position: it will fold if you push it hard enough in the appropriate direction. This is how a classic pocket penknife works. In English literature, a knife equipped with a similar mechanism is called slip joint folder, or a folding knife with a sliding joint (or rather articulation).
I could not find the corresponding Polish term. Oh well, it doesn't matter what it's scientifically called; what matters is how it works. The spring, attached at one end to the upper edge of the handle, with its other end presses on the disc-shaped surface of the back of the blade. And this surface is designed in such a way that both opening and folding the knife causes the spring to bend or unbend; at the same time, it provides a certain resistance, which allows you to keep the knife either in the open or in the closed position (Fig. ). But if in the folded state the spring holds the blade quite reliably, then in the open position such a knife cannot be called one hundred percent safe. In practice, you have little to fear if you only use your knife for light, well-controlled cutting—for example, opening mail or sharpening pencils. Perhaps that is why such models are becoming a thing of the past, now they are produced in small numbers. Even typical multifunction penknives are now increasingly being equipped with mechanisms that allow at least one, the largest (main) blade, to be held open.
