All about knives. Folding Knife Making Instructions Manual Knife Openers
barb 09-06-2007 01:11
IMHO Axle fitting 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 sold on knifekits (
DRPPK - Precision Pivot Assemblie) then it is possible without a lathe.
And what happens? If I don't have a turner, then I can't do it anymore?
SiDiS 09-06-2007 14:45
quote: Originally posted by RIA:
Fitting an axle without a lathe looks crazy.
Disagree
drill enough
RIA 09-06-2007 15:14
SiDiS well, uh .. I agree kanesha but ..
SiDiS 10-06-2007 01:05
By the way .. on folds with liner, compressor, axis and arches, very precise adjustment of the axis to the hole and vice versa - not critical. Keep within ten - it's normal. On these locks, the gap on the axle and 0.2 - 0.3 mm in the open state is imperceptible because these locks work on the principle of sampling the gap.
But on the back there is a completely different picture. With a perfectly fitted lock, the gaps on the axes of rotation of the blade and the backing are very critical and, ideally, should be within 2-3 hundred square meters maximum. A gap of ten on any of these elements will be expressed in 3-4 at the tip, and on both - 0.5 mm and more. This is not always felt, because the spring on the back is powerful.
SanDude 26-06-2007 10:47
I read on the American forum about how to make a hole in the blade so that it is perfectly even and so that the diameter deviates by no more than 0.005mm
Here's what they advise:
In the process of work, check the hole diameter 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 until a little less is hardened and make the hole a little less than necessary.
2. After hardening, go through the carbide reamer.
this is quite enough, and will allow you to get an accuracy of up to 0.03 mm, depending on the left allowance
quote: Originally posted by SanDude:
3. Then finish with a cylindrical bronze lapping.
this is already 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 beating is that they look at the machine badly
RIA 26-06-2007 23:01
quote: Originally posted by SanDude:
2. After hardening, go through the carbide reamer.
Eh .. They would still have some hosh .. and shoby is not expensive ..
SanDude 03-07-2007 07:21
I spoke with Ralph Darrell from www.knifekits.com He said that the best smoothness will only be obtained from the reamer after hardening. During hardening, he says, the hole geometry is always violated. With lapping, he uses 400 or even 600 grit diamond paste.
He uses a friction bearing only made of stainless steel. Bronze does not recommend. Advises gaskets bronze and not Teflon.
SiDiS 04-07-2007 12:42
quote: Originally posted by SanDude:
He uses a friction bearing only made of stainless steel. Bronze does not recommend.
Strange opinion, IMHO. Bronze holds good punch, and pleases with low friction coefficient with steel.
quote: Originally posted by SanDude:
Advises gaskets bronze and not Teflon.
Puzzled "... not in any way ..."
SanDude 21-07-2007 13:17
How do you adjust the bushing and spacer in thickness to maintain the parallelism of the ends?
SiDiS 21-07-2007 14:09
Yes, a couple of hundred square meters in thickness in both directions will not spoil anything
And if you are interested in the method, then I measure the thickness of the blade along with the washers and mill the spacer to this size.
SanDude 21-07-2007 22:56
Instead of the role of a spacer, I have tubes. 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 the lock was invented, allowing the blade to be fixed in the open state. But in fact, the history of folding knives is much older.
A small excursion into history
Folding knives have been known since the days of 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 got out of it with a simple turn. IN open position the blade was held solely by the friction force, and when cutting - by the support of the shank on the handle. Of course, this design was primitive and short-lived, the knives often failed.
The prevalence of folding knives both in ancient Rome and in other countries in later times is also associated with the fact that carrying 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 the south of Spain, Navaja folding knives appeared and became very popular. This was due to the tightening of anti-weapon legislation, which prohibited members 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 Revolutionary War. 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 everyday functions. Such "soldier's knives" were made by Karl Elsener's company, which later grew into the famous Victorinox.
Nowadays folding pocket knives, also called folding knives, folding knives, 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 during storage.
Modern folding knife design
A folding knife differs from a knife with a fixed blade primarily in that it has a movable mechanism that connects the blade to the handle. But, as with any knife, the main structural elements are the blade and the handle.
The folding knife blade has the same basic elements and parameters as the fixed blade knife blade. We wrote about this earlier in the article devoted to. But at the same time, it also has additional structural elementsassociated with the need to open the knife and fix the blade in the open position.
Manual knife openers
Finger hole - This is a hole on the blade, usually round or oval, located closer to the handle. With its help, the folding knife opens quickly and easily.
The pin on the blade - a special stop, for the installation of which a threaded hole is drilled in the blade. The pin is screwed into it. Basically, knives have a one-sided pin, it can be screwed onto the desired side of the blade - under the right or left hand. There are models equipped with symmetrical pins, they are located on both sides of the blade. This knife can be opened with both right and left hand.
Washer - this is the pin, which 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 ledge on the blade. When the knife is folded, the flipper protrudes from the top of the handle. The pressure on the flipper partially opens the knife. Further opening takes place either by shaking, or with the help of the thumb, or, if available, by means of an asist spring. The flipper also acts as a guard, preventing the palm from sliding onto the blade.
Wave - this is a hook on the butt, which, when removing the knife, 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 most proven method of opening, which is now rare. Mainly used in models with multiple blades or additional tools. Requires both hands to open.
Sometimes manufacturers combine opening elements: for example, a wave with a finger groove. Or peg and flipper like the floor automatic knives.
It is more convenient to open knives equipped with protruding elements - a pin, a washer, a flipper, but they reduce the effective length of the blade. In addition, any protruding element can 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 a blade, it should also accommodate folding and locking mechanisms. Therefore, the structure of the handle is more complex, and materials are used more durable.
The handle design of a typical folding knife looks like this. The base for the handle of the folding knife is an internal supporting frame (frame). These are two metal plates, or liners (liner), placed parallel to each other and connected by screws or rivets. In modern models, a screw connection is more often used. It allows you to avoid loosening of parts that may appear during the operation of the knife, regulates the softness of the blade stroke and facilitates the process of disassembling the knife when carrying out maintenance work.
A lock for fixing the blade and an automatic knife opening mechanism (for automatic and semi-automatic knives) are mounted inside the frame. There is a groove between the liners, in which the blade is located. The presence of the groove is provided by the rear tab, which forms the ridge of the handle. When we fold the knife, almost all of the blade goes into the gap between the plates.
On the outside, the liners are decorated with linings, which can be either natural (wood, bone) or artificial (fiberglass, micarta, carbon) materials. The overlays may be absent, and then the role of the handle is played by the frame plates, which in this case are made thicker. The pads serve not only to decorate the handle, but also improve the grip, prevent the knife from sliding in the hand and generally increase the ease of use. The combination of the frame with overlays gives the structure the required rigidity and strength.
In the front part of the handle, an axle is mounted in the plates, around which the blade turns when the knife is opened and closed. There is also a blade rotation limiter in the open state. Between the side plates and the blade inside the groove there are also spacers, which in expensive knives are usually made of bronze or copper, and in cheaper ones - of Teflon.
If we talk about the geometry of the handle, then in shape they can be concave, convex, rectangular, wedge-shaped, with or without finger recesses. In cross-section - round, 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 knives with a fixed blade, which we already wrote about in the article on the structure.
Security elements
Modern models of folding knives are equipped with fairly reliable blade clamps. However, there is still a chance of accidentally folding the knife. Spontaneous opening of the knife can lead to serious injury - the blade can sink 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, fuses are placed in the cut-out area of \u200b\u200bthe locking lever. For knives equipped with a linear lock, they are located in front of the handle, under the thumb.
In semiautomatic 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 activated by accident, when the folded knife is in the pocket.
Knives, supplemented with clamps, are comparable in reliability to knives with a fixed blade.
Clip for carrying
For convenient carrying of a knife in a pocket or on a waist belt, almost all folding knives are equipped with a special clip, or clip, which usually looks like a steel spring 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 fastening, 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 point either downward or upward.
In most cases, the clamp is attached to the handle with screws. If necessary, you can remove it and carry the knife in the sheath. There are clamps and fixed ones, but such knives are quite rare.
Elements that expand percussion possibilities
The folding knife can be used without opening the blade. For example, in self-defense, when the knife acts as a palm stick. In this case, the blow is applied by the parts of the handle protruding from the fist. To increase the effectiveness of a strike in tactical knives, the end of the handle can have a triangular shape or a special striking element in the form of a cylinder, cone, or pyramid.
Additional elements
Folding knives can be equipped with additional elements that expand the functionality of the knife. This can be a can opener and bottle opener, a corkscrew and an awl, pliers and a screwdriver. Their number can be from one to several dozen. Their number and equipment depend on the purpose of the knife. So, in addition to the basic set of tools, tourist knives 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 sizes and weight, but also a reliable mechanism for opening and fixing the blade. The convenience in use and the opening speed of the knife depend on this, which can be important, as well as its strength and durability. Types of locks and their structure are discussed in.
The variety of types of knives does not allow the topic of their own production to dry out. The knife is an ideal assistant not only in the household, but also during hunting, fishing and other field conditions. Someone probably may need a knife in case of tough self-defense. But it's best to try to avoid using the knife as a weapon of self-defense. There are less dangerous to human life and more, so to speak, legal items of self-defense. But life is life and you never know when, how and with what it will have to be protected. It is convenient to carry camping and hunting knives in a sheath, but in urban conditions a cleaver on a belt will look quite wild and will naturally attract close attention of law enforcement agencies. Therefore, there are folding knives that are convenient to carry in a trouser pocket. Today we are going to make such a thing.
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 for informational purposes and is aimed at readers who already have an idea of \u200b\u200bmaking knives, so the description is given rather short; but from the photographs you can understand almost every step of the work.
To make a folding knife we \u200b\u200bneed a titanium plate, although you can use stainless steel or some other good steel. Naturally, it all starts with making a template, the shape of which you will then transfer to a steel strip.
First we will make the liners of the folding knife handle. We outline the shape of the liner on the 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. We make the second liner. To do this, attach the finished liner to a strip of metal and drill two holes through and through. We cut the threads into them, fasten the liners with screws without a cap and cut out the second liner, using the first as a template. Next, we process the paired liners on emery and files, approaching as close as possible to the contour line of the liner.
It was the turn of the making of the folding knife blade and the back of the handle. We act in exactly the same way: templates, transfer to a titanium strip, sawing out and processing on emery.
We drill holes in the liners for attaching the back of the knife handle. We collect the knife and look where there are inconsistencies, cracks. If necessary, we modify these places, using files to achieve the perfect alignment of all parts of the folding knife.
We put on the second liner and drill additional holes for fastening the back of the knife. You can fasten the parts of the knife handle using special screws by pre-tapping the threads in the holes. The screws are convenient in that, if necessary, the knife can be easily disassembled and performed any modification. We expand all screw holes 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 covers of the knife handle. We glue them on the liners with super glue. Now we drill holes for the screws through the liners into the metal plates. The holes in the trims must not be through. Now we put the knife in the acetone bath to dissolve the superglue.
Chamfer the blind holes of the metal clasp knife and cut the threads into them. We attach the liners to the liners with screws. We adjust the overlays by grinding off excess metal on emery to fit the shape of the liners.Next, we make the final grinding of the knife handle.
From the inside, on the front metal linings, 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... Cut the thread into a die.In the back of the handle we cut out a cone-shaped ( dovetail) groove for leaf spring.
All metal parts of a folding knife are hardened using a homemade forge or a gas burner.We will make the middle part of the linings from any available material: wood, bone, plastic, plexiglass, textolite, etc.
We cut out and grind the plate, adjusting its shape. The job requires precision, so adjust the middle pad slowly and periodically trying it on. After that, we drill blind holes in the liners for attaching the wooden lining. And cut out the L-shaped slots.
Remained the case for the castle. We drill holes for the lock at each end of the liner. We connect them with a slot. Then we make a cross-cut and get an L-shaped slot that forms the locking plate. We harden it with a gas burner and bend it to the side by three or four millimeters.
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 plane of the spring.We sharpen the axle screw, making it rectangular. We mill the screw slot 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 handle linings. We make bevels on the blade of a folding knife.
We collect the knife. But the axle is put on a thin washer, a blade, another washer. Then a second liner is put on. Insert the middle pads by snapping them into the L-shaped holes. We tighten the screws with a flat special wrench.
The urbanization of the modern world has led to an increase in the popularity of folding knives (in common parlance - "folding knives" 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 wearing it is absolutely legal.
It can be used for a wide variety of operations - opening envelopes and cardboard boxes, opening plastic packaging, cutting tape, etc. In an emergency, it can also be used as a personal defense weapon. There was even a special term for the knives of a city dweller - "everyday-wear knife" or EDC knife (from the English-language abbreviation EDC - Every Day Carring).
The activities of human rights organizations in many countries of the world have 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 settings. 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 wide variety of operations - breaking doors, punching office partitions and of course, rope cutting, etc. These knives are often used as auxiliary knives in army units, as well as tourist (camping) knives or knives for working in the field.
The main types of blade retainers
The achievements of modern metallurgy and inorganic chemistry, the introduction of new technologies for processing materials make it possible to bring to life the most daring design ideas... Close interaction of knife masters with experts in hand-to-hand combat allows you to create original models of tactical knives with increased fighting 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 high 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 hand sizes, they can have a leading right or left hand. For those who are not an expert in the field of bladed weapons, the variety of designs creates certain difficulties when 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, in the manufacture of which the most advanced technologies are used.
A typical folding knife is a single-edged blade attached to the shaft of the handle. When folded, the knife blade is hidden in the handle.
The main structural elements of the knife are the blade and the handle.
In the classic version, the blade rotates 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. Such knives look very original, but they are inferior in reliability to knives of a classical design. An exception to this rule is hinged knives with a transverse blade opening.
In most folding knives, when open, the blade is in line with the handle. Among the 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. At the same time, the knife turns into a knuckle-duster grip knife, such as the well-known "push daggers", originating from the hidden daggers of the Wild West card players. The advantage of such knives is the simplified technique of striking - the blow is similar to a fist blow.
The STI company even developed the Tai sabaki knife (from the name of the Japanese technique for turning the body), in which the blade can be fixed in six positions, which allows expanding the technical arsenal of striking.
STI knife with blade fixation in several positions
By the principle of opening, the 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)
For knives with automatic opening, you only need to press a special button or a folding trigger guard on the handle. In the knife literature, such knives are often called "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 are the "Italian stiletto" and its many clones.
Semi-automatic knife opening buttons and Italian stiletto
In fully automatic knives, both opening and closing of the knife are 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 is completely retracted into the handle. This allows the use of dagger-type blades with double-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 company "Mikrotek", known for the high quality of knives, have managed to create automatic knives, which are practically devoid of this drawback. But the price to pay is their high price.
Microtech automatic knives
The legislation of many countries, including Russia, classifies automatic knives with a certain blade length as criminal, and their wearing is prohibited in these countries. These restrictions do not apply to semi-automatic knives.
In order to avoid the risk of injury from accidental opening of such knives in a pocket, they often have a special safety device.
The main advantage of automatic and semi-automatic knives is that they can be quickly put into working condition with one hand. It has great importance in knife fighting, as well as for people who, as a result of professional activity, can act 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, consequently, less reliability. Cleaning the mechanism is a rather complicated procedure, especially in fully automatic knives, where only qualified personnel can do it. Therefore, automatic and semi-automatic knives are not well suited for field conditions.
These drawbacks 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 Wehrmacht airborne units, which in a modified version is still produced today. The knife is very reliable, has a simple design and is easily disassembled for preventive cleaning.
Fixing the blade in the open position is provided by special structural elements - locks (in English literature - lock). Such a fixation of the blade ensures safe use of the knife, especially during operations where its stabbing action is required.
On the first primitive folding knives, the lock-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 clamps are most common - 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 reliable fastening of the blade in the open position.
A kind of lock on the butt of the blade
Back up lock considered the most reliable. But knives with this type of lock are difficult to fold with one hand. In addition, there is the possibility of accidental folding of the blade when the handle is squeezed strongly.
Knives that use a kind of back up lock, which was originally used on the Spanish Navaja knives, are free from this drawback. A similar lock is used on the South African Okapi. In this lock-retainer, the blade is locked in the open position by the projection of the butt, which enters the hole on the spring bar of the lock. To release 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 retainer strip can come out of engagement with the heel of the blade.
Much less common is ring lock, which is used on the Opinel French 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, just turn the ring so that its slot aligns with the blade line. 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 hinged-frame type knives. In these knives, the main structural element is special frames or hinges, which simultaneously ensure the fixation of the blade. Such knives are characterized by high reliability of the blade locking in the open position while the knife is held in the hand. They have a symmetrical shape, making them equally comfortable for both right-handers and left-handers.
Frame knives consist of two frames, the planes of rotation of which are mutually perpendicular. Among the domestic knives, these include "Chizhik" by master Konstantin Sazhin and "Skat" by "NOKS" company.
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 the hinge knives, pantograph knives have the most complex design. Typical examples are the German Paratrooper knife and the Smith & Wesson Power Glide knife.
Knives with lateral blade rotation
Knife "Paratrooper", patented in Germany in 1938, is sometimes mistakenly called a knife of the Wehrmacht airborne units. An indispensable condition for knives for parachutists is the ability to open it with one hand, while the Paratroper cannot be opened 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. A unique feature of this knife is that the open blade is longer than 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 knife balisong.
Articulated knives
In most folding knives, when folded, the blade is completely hidden in the knife handle. Only part of the butt protrudes from the handle (for this reason, double-sided blade sharpening is not used in folding knives). However, there are knives in which, when folded, the blade enters from the handle - semi-folding knives. Admiral D'Estan's daggers are a classic example of such a knife. This design combines the advantages of large fixed blade knives with the small size of folding knives. This design of knives in the last century was quite common on hunting and game knives. It is with such a knife that Kuzmich cuts pineapple from the garden in the popular comedy Peculiarities of the National Hunt.
Semi-knives
The disadvantage of these knives is the need to use a scabbard 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 unique design had a Soviet knife designed by A. I. Shilin, deputy chief designer of the Kovrov plant number 2 named. KO Kirkizha (State Union Plant No. 2). The knife was developed as part of the competition for the selection of a folding knife for the officers of the Soviet army, which was held in 1944, and took second place in this competition. According to some reports, a small trial series of these knives was made in 1945. However, for unknown reasons, the knife never entered service. The knife had a double-edged blade. When folded, the blade was two-thirds of its length hidden in the handle. To carry the knife, a wooden scabbard was used, inside which there were special hooks that ensure the automatic extension of the blade to its full length when the knife is removed. In addition to the blade itself, the knife handle contained a standard set of tools required for everyday life - awl, corkscrew, screwdriver, can opener and bottle opener.
An officer's knife designed by A.I.Shilin and its modern Chinese counterpart
The ideas laid down by Shilin have now been used by the Chinese in the development of a special knife used by the Chinese police.
The blade is the main part of the knife. It is on him that the stabbing and cutting properties of the knife depend. The main factors that determine the operational characteristics of the blade are the material and technology of its manufacture, as well as its shape and cross-section. Blades of modern folding knives are made of corrosion-resistant types of steel. 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". Several dozen different grades of steel are currently used in the knife industry. Since 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 making 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 complicates the straightening of 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 provide a good quality of the blade. It is with this that the high cost of folding knives from well-known manufacturers is associated with modern equipment and carefully monitoring the quality of the blade.
The hardness of the cutting edge is expressed in Rockwell units. Usually folding knife blades are hardened to 42–60 HRC units. The larger this number, the longer the knife keeps sharpening, but for this you have to pay with less resistance to shock loads and the complexity of sharpening the knife. Conversely, at low HRC values, the cutting edge is more plastic, easy to sharpen, but poorly holding the sharpening. With an increase in hardness above 61 HRC, the blade of knives with a normal butt thickness becomes very fragile. Blade of blades hardened to 42 units. or less, has low strength and is difficult to cut common materials. This figure is not shown 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 the 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 a locksmith or carpentry tool to sharpen it.
The surface of the blade can be polished, matt, blued, chrome-plated or have a special protective coating.
Polishing increases the blade's resistance 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 bluing the blade, a thin layer of a protective oxide film is created on its surface, while the blade acquires a dark color. When chrome 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, the blade coating made of synthetic materials ( epoxy resins, Teflon), which provide high resistance to moisture or acidic and alkaline environments. Because this coating prevents the blade from glaring in the sun, it is often referred to as "anti-reflective" and is often used for 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 produced by forging several layers of steel with different carbon content. As a result, a beautiful pattern appears on the surface of the blade. Modern industrial production of Damascus steels makes it possible to design in advance the shape of this pattern ("mosaic damascus").
The combination of low carbon steel strips for ductility and high carbon strips for cutting edge hardness results in blades with excellent performance. In addition, the cutting edge of Damascus steel knives has micro-teeth that increase the cutting ability of the knife.
Damascus steel knives look very impressive. However, it should be borne in mind that the risk of getting a defective blade made of Damascus steel is much higher than when purchasing a knife with a conventional steel blade. This is due to the rather complex technology of manufacturing such steel.
Dales, which are often called blood channels, 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 stiffness 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 a one and a half sharpening.
Folding knives use the most different shapes blades. For ordinary household operations, knives with a straight blade or a blade converging to a point are preferred. The disadvantage of the classic shape 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 shape of a blade with a reinforced edge began to be used.If the knife requires increased cutting properties (knives for self-defense), blades with a blade that have a convex or wavy shape are used. At the end of the last - the beginning of this century, knives with a sickle-shaped blade, which is characteristic of 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, for the same purpose knives in which the blade is angled to the handle. This idea got its maximum development in the STI pistol grip knives.
Flat wedge has high performance, combining blade strength and sharp blade. Due to the uniform distribution of force, it cuts well soft materials of large thickness. Disadvantages - the complexity of sharpening, copes poorly with cutting hard materials.
Chisel profile - differs in manufacturability and ease of sharpening. It is widespread on the blades of Asian knives. It has excellent chopping properties, it cuts well non-thick materials.
Flat concave wedge and its kind of flat-concave wedge with supply is distinguished by simplicity of manufacture, easy to correct and sharpen, perfectly performs shallow cuts. Disadvantages - low mechanical strength, difficulty 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.
Pentahedral profile combines manufacturability, strength, good cutting qualities, good edits. 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 Armyknives" the number of such tools can reach several dozen. Such multifunctional knives are called "multitool". For self-defense, knives with two working blades are also produced, which allow hitting the target during forward and reverse movement of the hand without changing the orientation of the knife or changing its grip.
A 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 a sharpening is called "sereyitor" or "sereyitornoy" (from the English. serrated "Sawtooth"). In self-defense knives, serrated sharpening facilitates cutting through thick outerwear 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 seritor 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 an appropriate specialist. 
Most modern folding knives are designed to be opened with one hand, either right or left. For this, at the base of the blade there are special elements - cylindrical pins, round or square dies or holes in the blade (the round hole is protected by a patent belonging to 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, 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 trousers are made of thin material, then after several cycles of pulling out the knife, they will most likely be broken.
Much less common on modern knives is a special semicircular cut on the blade. It is most often used in models with several working blades or tools, or in knives without blade fixation, which are well known to the older generation from Soviet times.
Another element that makes it easier to open 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 slightly move the blade by pressing the flipper with your finger, and then bring the blade to the working position with an energetic swing of the hand. In semi-automatic knives, there is no need for such a swing, the blade is adjusted to the working position by a spring mechanism automatically.
In addition, the flipper acts as a kind of guard, preventing the hand from sliding onto the blade.
The most common grip for folding knives is the straight diagonal (fencing) grip. In this grip, the thumb rests on the butt of the blade. For more comfortable control of the knife, a special notch is made at the point of contact of the thumb on the butt of the blade. The part of the handle adjacent to the blade can also have a notch.
Grips
The handles of most modern knives have a batch typesetting design, consisting of an internal frame (frame) in the form of metal strips - liners (liners) and linings. Blade fixing elements, an automatic opening mechanism (for semi-automatic and automatic knives) are mounted inside the frame.
Simple monolithic handles with a groove for a blade or a handle made of a bent steel strip are rare in modern knives, mainly in 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 loosening of parts that appears during the operation of the knife, to regulate the "softness of the blade", facilitates the disassembly of the knife for maintenance work. Most foreign folding knives use screws with a curved slot of the "torx" type. To work with such screws, a special tool is required - screwdrivers or socket wrenches with a corresponding head. Some companies include such keys with the knife, otherwise they have to be purchased additionally.
The shape of the handle, its cross-section, as well as the texture of the linings determine the convenience and safety of using the knife. The rectangular cross-section of the knife is technologically advanced in production, but not convenient when performing long-term work with the knife. The round handle fits comfortably in the hand, but does not allow you to feel the orientation of the knife by touch. Therefore, the most convenient handles are oval. The rectangular shape is compact, but at the same time does not provide protection against slipping of the hand onto the blade. The wedge-shaped shape of the handle better protects the hand when working with the tip of the knife, but when trying to pull out a knife stuck in a dense material, the hand will slide off the handle. Small pocket knives often have this shape for performing small household tasks.
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. This is the shape of the handle that the time-tested Finnish knives have.
Even more comfortable is the handle of the convex-concave shape and the shape that is often used on tactical knives. Modern knives increasingly use complex shaped handles that take into account the ergonomics of the hand. However, its configuration is calculated under a medium-sized hand, 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 linings is their "warmth" and the beauty of natural material. Expensive knives can be made using exotic woods with a very beautiful texture. The main disadvantage is poor wear and moisture resistance. Multilayer varnish in some way solves the problem, but it reduces the reliability of holding the knife in the hand. Horn and bone are another naturally occurring material. Handles made of these materials polish well and look very beautiful. Disadvantage - they can crack and are easily scratched. Metal pads 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 with a notch on them. 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 allow simulating the structure of natural materials and at the same time avoiding their inherent disadvantages, although they lose weight to them. One of the most popular materials of this type is one of the types of micarta PCB. Recently, more and more use of lining from different types plastics, such as ABC, Zitel, Kydex and others. These materials are technologically advanced, moisture resistant, durable and resistant to environmental influences. They make it possible to produce onlays of any shape with any pattern of texture - from the simple roughness inherent in the material of the onlays or rectangular notches to specially designed surface types. For example, CRKT's For Those Who Serve knives use a special honeycomb structure to prevent the knife from slipping in the hand. For the same purpose, rubberized inserts or structural elements-inserts such as sandpaper serve.
Many folding knife models have a round hole in the end of the handles for attaching a lanyard or lanyard to it.
Security elements
Although modern blade retainer designs are quite reliable, nevertheless, as noted above, there is the possibility of accidental blade folding. To prevent this, modern knives have special fuses. For knives with a butt lock, they are usually located in the notch area of \u200b\u200bthe locking lever. On models with a linear lock, they are located at the front of the handle under the thumb. Supplementing the blade retainers with fuses practically turns the knife from a folding knife into a knife with a fixed blade.
For the safe carrying of semi-automatic and automatic knives, a safety device must prevent the knife from opening in a clothing pocket if the trigger is accidentally pulled. Therefore, in such knives, the safety catch often has a double action - it blocks the blade in the closed and open state.
Clip (clip) for wearing
A steel spring clip is an almost indispensable attribute of modern folding knives. In the knife literature, the term "clip" (from the English. clip clip, paper clip). It provides a convenient carrying of the knife in the pockets of clothes or on a trouser belt.
Many knife manufacturers make the clamp adjustable - that is, it can be attached to different sides of the handle depending on whether the owner is right-handed or left-handed. In addition, sometimes it is possible to change not only the side of the clamp fastening - at the base or at the end. In this case, in the pocket, the knife will be oriented either with its tip down or up. Some experts believe that when carrying the knife upside down, there is a possibility of a cut when trying to pull the knife out of the pocket if, for whatever reason, the blade comes out of the handle. At the same time, with such an orientation of the knife, it is more quickly brought into working condition.
In some models of folding knives, the clip attachment point is not in the Z-shape, but in the shape of the letter "L" or "P". In this case, when carrying a knife in a pocket of clothes, the upper part of the handle is hidden from outside view - only the spring plate of the clip protrudes from the pocket. Outwardly, it looks like a regular ballpoint pen.
Elements that expand percussion possibilities
For self-defense purposes, 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 the parts of the handle protruding from the fist. In tactical knives and self-defense knives, the end of the handle often has a triangular shape or a special striking element in the form of a cylinder, cone or pyramid to increase the effectiveness of such blows.
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 melee weapon, can only be determined by an expert by law. Therefore, when purchasing a knife, you should always ask the seller for a copy of the information sheet for the certificate of certification tests (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 melee weapon test. Moreover, it is best if such tests were carried out by the head organization “Forensic Center of the Ministry of Internal Affairs”. It is better to always have a copy of this document with you, which will allow you to avoid unnecessary conflicts with law enforcement officials. 
Most of the quality folding knives on the Russian knife market are products of foreign companies. Unfortunately, most of the serial domestic folding knives are inferior to foreign ones in almost all respects, and among them one can rarely find original models. 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 (a saboteur's 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 handcrafted folding knives, which are not inferior to foreign ones (including in price). As an example, the folding knives of the Ural master Urakov and the workshop of the Shirogorov brothers are shown. The rapid pace of development of the Russian knife industry allows us to hope for the emergence of domestic folding knives that are not inferior to foreign models.
Anatoly Fomin. Magazine "Brother" 2013-01
In the most simple models the blade does not lock in the open position: it will fold if you press it quite hard in the appropriate direction. This is how a classic pocket penknife works. In English literature, a knife equipped with a similar mechanism is calledslip joint folder, or a folding knife with a sliding joint (rather a joint).
I could not find an appropriate Polish term. Well, okay, it doesn't matter what it is called scientifically; how it works is important. The spring, attached at one end to the upper edge of the handle, presses at the other end on the disc-shaped surface of the rear of the blade. And this surface is designed in such a way that both opening and folding of the knife makes the spring bend or unbend; at the same time, it provides a certain resistance, which allows you to hold 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 100% safe. There is little to no fear if you only use the knife for light, well-controlled cuts, such as opening mail or sharpening pencils. Perhaps that is why such models are becoming a thing of the past, now they are not produced much. Even typical multifunctional pocket knives are now increasingly equipped with mechanisms that allow you to hold at least one, largest (main) blade in an open position.
