Cleaning wires from insulation. How to strip insulation from different types of wires
An electrician's work is impossible without special devices. To perform such a simple operation as cutting wiring, connecting switches and sockets, you will need a stripping tool. To strip the wiring, you should use a special hand tool for removing insulation from wires: strippers, strippers.
Of course, if you need to strip a couple of wires, you can get by with regular kitchen knife, but if there is work to be done on installing electrical wiring in an apartment or in a house, then an ordinary knife will not be suitable for these purposes. His blade is too uncomfortable. And the work of a professional electrician is simple table-knife should not be used, since its handle may not be made of dielectric material.
Electrician's knives: features and types
A proper electrician's knife does not necessarily have a straight blade, because it is often necessary to make circular cuts on the wires, and this is more convenient to do with a curved blade. Of course, you can remove the sheath from the wiring with a regular knife, cutting the top insulating layer lengthwise and the contact sheath in a circular motion, then removing the sheath like a stocking. But, if the knife blade, its dimensions and handle do not meet certain requirements, the conductor itself can easily be damaged, especially if the wires are thin.
To simplify circular cuts, notches are made on the knife blade for different diameters of wires; by placing the cable there, you can make a cut on the braid in a circular motion without fear of damaging the core itself.
The general requirements for a knife for electrical work are as follows:
- It is better not to choose a knife for removing insulation big size, this will allow you to work in tight spaces (panel, closet). The dimensions of the blade itself should also be miniature, so as not to cut off excess in the wiring bundle. In addition, the small blade is not long length It fits better in the hand and is more convenient for stripping thin wires.
- The cutting edge must be straight. This will simplify the operation of cutting double-braided wires - when you only need to remove the outer insulation and leave the inner one intact.
- The handle does not have to be anatomical. The shape should allow you to determine by touch where the tip of the blade is.
- The blade material is carbon steel, this will allow you to maintain the required sharpness longer.
- The handle must be made of dielectric, durable material: Durable plastic, carbon fiber to prevent damage electric shock during work. “Instructions for the use and testing of protective equipment used in electrical installations” - clause 2.16.
An electrician does not need a knife with a sharp blade. Firstly, during many small operations, especially in cramped and dark rooms, the electrician will involuntarily touch the cutting side with his fingers, and secondly, the metal wire will be easily damaged by a razor-sharpened blade. Thirdly, when working with a bundle of wires with a sharp knife, it is easy to damage adjacent wires.
Important! When stripping cables, the knife should be held so that the blade is at an acute angle to the cable. Otherwise, the soft metal core (copper or aluminum conductor) may be damaged. Remove the braid with light movements away from you, cutting off the shell in pieces, just like sharpening a pencil.
If the knife was purchased from the electrical department, the handle should indicate what voltage it can withstand. If you use a homemade product in your work, before removing the insulation, you need to take care reliable protection handles, wrapping it with electrical insulating material (cable braid, electrical tape). Of course, it is impossible to call this method of protecting the handle completely safe.
Electrician's knife with heel
This product is one of the types of electrician's knife. It is also called plow. This convenient device to remove the shell. It has a short, inwardly curved blade; at the tip of the blade there is a special device called the “heel”. The main purpose of this “heel” is to limit the depth of the cut when working with double insulation, when it is necessary to remove upper layer braid, and not affect the insulation of internal wires. 
Important! Before removing the sheath from the cable, you need to make sure that there is no voltage using an indicator screwdriver!
The platform at the tip of the blade facilitates the longitudinal sliding of the device when removing the top layer of protection and prevents the tip from catching the internal wires. The device is excellent for cables with hard cores (VVG), but it is worse at removing a soft sheath, such as PVA (it worsens the sliding of the heel). In general, this is useful tool for removing insulation during the work of an electrician.
Knife with beak
Specific product. Not all electricians use it in their work. For some this tool will be convenient, for others it will not. It is somewhat similar to the previous knife, only the curve of the blade is smoother, and there is no “heel” at the tip.
This curved, beak-shaped inner edge makes it easier to cut the braid in a circular manner before removing it. It can also be used for longitudinal cuts, but be careful, because there is no limiting “heel” on the blade. May be inconvenient for inexperienced electricians, as the cutting depth must be adjusted manually.
Knife with hook
It is considered a professional instrument. Its blade is short and straight with a hook at the end. The sharp edge is either absent (only the hook itself is sharpened) or located on the opposite side as an addition. Suitable for stripping all major cable types. 
This knife is convenient for cutting the insulation from the cable lengthwise. Many models are equipped with other devices that allow you to make circular cuts before stripping the insulation from the wire. It is very popular among professional electricians.
Pullers
You can strip the insulation from the wires using special pullers. In essence, these are universal devices for stripping wires. Can contain multiple blades different shapes and length. But the basis is a special clamp that allows you to make a circular cut in the braid of cables of different diameters. 
Such tools are more convenient because they make it possible to manually select the diameter when cutting the cable braid without fear of damaging the conductor. It is not difficult to use such strippers; you just need to fix the cable being processed in the clamp and rotate the insulation stripper from the wires around it once.
Strippers
Perhaps the most common type of wire stripping tool in the arsenal of a professional electrician. These devices are electrician's assistants for conventional manual, semi-automatic or automatic wire stripping. They make stripping insulation from any cable much easier with their help.
It is very convenient to use a stripper to remove the top layer of the protective shell from stranded wires. The cutting depth can be easily adjusted, which allows it to be used when stripping cables with large and small diameters. Stripping thin cables is easy. 
The device also has a special limiter that allows you to select the length of the dielectric shell to be removed. When stripping a long length of wire, the limiter can be easily removed. 
Often, wire strippers are complemented with other accessories that make them a truly multifunctional tool. For example, their design may include press tongs. With their help you can crimp the ends of the wires. Crimping can be carried out using various sleeves and tips, allowing for their subsequent connection to electrical appliances. Strippers are often used as crimpers to connect one stripped end of a wire to the other without soldering using terminals. Some models may be equipped with wire cutters. 
Advantages of strippers (compared to knives):
- can be used to remove the sheath of conductors of very thin diameter (cross section from 0.05 mm2);
- in addition to stripping, they are used as cutters or press pliers to crimp the tip of the conductor;
- it is permissible to use when removing insulation from wires with any electrical insulation (silicone, polyvinyl chloride, rubber, etc.);
- with their help they can easily remove electrical insulation even from multi-core wiring, cables, twisted pairs;
- will not damage the current-carrying part even for conductors made of soft metal (aluminum, copper);
- easy to use;
- they cost little.
Finally, if you don’t have a professional tool or a convenient knife at hand, you can use a regular soldering iron to remove the insulation from the wires. Before cleaning electric wires, its tip is heated to the appropriate temperature, then the wire is leaned against it and twisted around the axis, burning through the insulation.
After this, the sheath can be easily removed, and the core will remain intact. To the disadvantages this method cleaning can be attributed to the fact that, when melting, the plastic shell will emit unpleasant and harmful smoke. Do not use a soldering iron to strip cables with rubber coating(since the rubber will simply burn) or coated with flammable material.
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The wire stripping tool is a professional equipment and if you are not a professional electrician, you are unlikely to need it. If you need to connect one socket or switch, a sharp knife and straight hands will be enough.
Why only a special tool?
Modern apartment in 100 square meters– this is 100 sockets and 20-30 switches. In total, this is about 300 contacts, not counting junction boxes, shields, additional connections and lighting fixtures. In total, the number of contacts from which it is necessary to remove insulation will reach 1.5-2 thousand. Carrying out such work without a tool for removing insulation is simply a waste of time and effort.
Even if you always do everything carefully, cutting the insulation on the wire with a knife for the thousandth time will still touch the core and damage its integrity. Subsequently, this may affect the quality of the contact connection; the core will break off or begin to heat up excessively in the damaged area.
Many items, such as the Legrand socket or other devices with automatic terminals, require the contacts to be stripped to a certain length. Should you measure 5-6 mm each time before cutting with a knife? Please note that there will be hundreds of such outlets for one apartment!
If you come to a customer to install electrical wiring and you don’t have a professional tool for removing insulation, no one will take you seriously!
What's on the market
The undisputed leader in this regard is the German company Knipex. The range of special devices for removing insulation is quite wide, we will focus on the best:
The specified tool is best combination price/quality. Or rather, it's simple best quality hand tools for removing insulation, which is. The cost of analogues from China or made in Russia is significantly, ten or even twenty times lower. For example, the Russian insulation stripping tool KVT WS 04B will cost you 22$ and similar crafts from China can be ordered at 10$ per kilogram.
KVT WS 04B is a Russian instrument. Works great. Not for long.
This whole tool will do an excellent job of removing insulation as well as Knipex. but only 2-3 months, after which the knives become dull, the mechanism becomes loose, you have to apply more and more force, the accuracy of the work becomes worse and worse. Eventually you start using your wire stripper again.
A professional tool is worth the money, because... allows you to earn faster, easier and more
Video review of strippers from different manufacturers
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Methods for removing dielectric
In electrical installation, working with radio equipment and electronics, such a process as exposure of the cable core cannot be avoided. It is produced mechanically, without focusing on the technique, in the following ways:
- Heating the stripping area to the melting temperature of the vinyl shell. This is done with the tip of a heated soldering iron, a lighter, or a specially made device with a thread made of a refractory metal, for example, nichrome. Not the most pleasant method due to the pungent odor. There’s also a residue left on the palm of your hand that reminds you of this process for weeks. It is better to use this method not on wires of small thickness and quantity.
- Mechanical method rests on the contact of pointed planes and the insulating coating. The simplest option is to use a knife. Use a regular one, or purchase a special cutter.
Because of cable production Available with two types of cores, Each has its own type of wire stripping tool:
- A mounting knife with a round blade is used for cutting round wires. The sharpened round piece cuts into the shell and cuts through it with a slight glide without damaging the metal.
- The flat cable cutter has a hook-shaped notch at the tip. It pries up the insulation layer, and due to sharp sharpening, resting the blunt end on the core, rips open the tube without touching the current-carrying part.
The use of these devices only requires skill when working with piercing and cutting objects and should be performed on a rigid base, but not on the knee. If the tip breaks accidentally, it can leave a deep cut.
Many people make their own knives from hacksaw blade. Important here correct angle sharpened part and a reliable handle.
Professional cleaning methods
Such tools are characterized by two methods of removing insulation. In a breaking action, the force is directed horizontally between two fixed points.
The cutting technique involves cutting the sheath in a circle and pulling it off the core. Both of these methods are combined in professional cable stripping tools.
They are divided into three groups:
- manual;
- automatic;
- semi-automatic.
In addition to this division, there is a classification by type of tool:
Stripper capabilities
This is the most common tool for stripping cable insulation, which comes in various modifications.
With its help without extra effort cleared:
- A separate vein.
- Twisted pair network cable.
- Coaxial cords.
- Fiber optic wire.
Hand tool
To use such a device, a number of manipulations are performed. Hence the second name - mechanical stripper for stripping insulation from wires. It has an external resemblance to pliers: the same two handles with a dielectric and jaws. Only these planes have special pointed recesses, calibrated for standard cable cross-sections of different sizes.
The pressing power is limited by the strength of the user's hands, so the maximum core area is limited, as a rule, to six square millimeters. The tool is quite versatile. Many varieties are a whole harvester. This includes crimping tips, cutting wire, as well as small fasteners, and making ring contacts.
The algorithm for using a stripper for stripping wires is simple:
- Insert the core in accordance with the cross-section and the desired length of the exposed part.
- Press the handles to bite.
- Turn in a circle.
- Remove the tool along with the vinyl tube.
The main requirement is right choice holes. Otherwise, the core will be damaged or the dielectric layer will not cut through.
The device is semi-automatic
For large volumes of work, it is more convenient to use this device. By appearance such a stripper resembles a mechanical modification, only a little more complicated. To strip the insulation, nothing is required other than placing the core in the desired socket and pressing the handles.
The peculiarity of semi-automatic equipment is to fix the length of the stripped section. This is convenient when large quantities connections of the same type, for example, in control cabinets or relay protection.
Automatic device
Like the entire family of similar equipment, this stripper has the same shape as other modifications. But here the user is freed from the need to select the right socket for the wire. The tool itself determines the force on the insulation. This device is capable of removing not only the protection from the cable core, but also the primary sheath of both round and flat sections.
Like most such devices, the automatic stripper performs many actions related to the manipulation of cable products.
To ensure that no additional problems arise when performing this type of electrical installation operations, there are some useful tips:
- When working with a coaxial cable, you must first remove the top protection using a soldering iron. Then remove the copper screen until the second dielectric layer appears. This step is best done with a knife.
- Small gauge wire (0.2 square millimeter and less) it is more effective to clean with a soldering iron or knife. You need to do the same with a paper dielectric.
- The enamel coating is removed with sandpaper.
- If the cable is not stripped from the edge, then the use of strippers is impossible. All that remains is to resort again to the help of a knife.
Which equipment to choose
Nowadays, it is difficult to surprise someone with a technical innovation. At every step, equipment of all kinds, prices and quality is sold. Same with electrical tools. The assortment is huge. If you need a stripper for several operations, there is no point in looking at expensive models. A simple tool for 200-400 rubles will do. For a higher quality and equipped device you will have to pay from a thousand to one and a half thousand rubles.
It is unlikely that you can buy a professional model with knives made of good steel, excellent sharpening and proven insulation for less than 2,500 rubles. In this case, there is no need to rush. You need to weigh the pros and cons and consult with specialists. Only in this case can you buy such a rather expensive instrument without compromising quality and wallet.
Several types of tools are used to strip insulation from wires: these are all kinds of knives, pliers, strippers, pliers (including automatic ones) and a number of others. How do they differ, how do they work and how convenient are they to use?
Hand tools
Hand tools for stripping wires are, as a rule, all kinds of pliers, pliers and pliers, which are simple in design and have a number of corresponding cutting edges.
Mechanical stripper
The cheapest and most common tool is simple manual strippers-crimpers, which combine pliers and wire cutters to remove insulation from the ends of wires. different diameters, as well as press pliers for crimping and crimping wires.
The stripper shown in the photo above also has a device for cutting studs and bolts. The main disadvantage of such tools is low quality due to the low price. In a store, before purchasing, it would be good to hold a specific copy in your hands to make sure that it is not a one-time Chinese craft.
Price – from 120 rub.
Stripping pliers
In terms of its purpose and functionality, this tool is completely similar to the stripper described above. But it is a little compact and convenient.
However, its price is also higher. When purchasing, you should pay attention to it functionality. U different models they differ. It happens that everything is limited only to cleaning the ends of the wires from insulation.
Price – from 700 rub.
A very common tool. Using a screw, it adapts to wires of different diameters.
To remove the insulation, you need to lightly bite and twist the wire, and then pull off the cut sheath. However, many people find this type of stripper inconvenient, although it is easier for them to work in hard-to-reach places.
Price – from 300 rub.
This multi-tool is focused on stripping round and coaxial cables.
Despite its unusual shape, it is comfortable to work with. Especially with large diameter cables. To strip the insulation, the cable is placed in the drop-down handle, lightly clamped and turned slightly to make a circular cut. Then the cut part of the insulation is intercepted and pulled together with the same cutting edges.
Price – from 800 rub.
There are a lot of knives various forms, designed for longitudinal and transverse cutting of insulation.
The most popular are those with a hook-shaped blade. The knife in the photo above also has legs that make it difficult for it to slip out of the cut shell.
Price – from 700 rub.
This knife has a small, retractable, adjustable blade that allows you to... rotary mechanism allows you to cut cable sheaths in any direction (lengthwise, crosswise).
Not all tools of this type are the same in their convenience, so in the store it would be good to first take a closer look at the ones you like.
Price – from 200 rub.
Semi-automatic tools
Semi-automatic wire stripping tools can significantly simplify the entire process and speed it up at the same time.
Tongs of this design are the most affordable option on the market and will undoubtedly be useful in household. They are not designed to work with wires with a cross-section of more than 6 mm 2.
When choosing a cheap model, you should personally check its performance. Alas, the quality of Chinese goods is not high, so in half the cases you may end up with a specimen that either squeezes the wire too much, cutting the wires, or, on the contrary, slips along the insulation. In addition, the durability of cheap models is also a big question. However, for one-time work it is quite suitable.
Price – from 180 rub.
However, there are expensive ones branded instruments, which are devoid of most of the listed disadvantages. But their price is appropriate - 10 thousand rubles is not the limit.
This is the most versatile tool designed for stripping wires. different types and different sections, to which it adapts automatically. Although some models also have manual adjustment for better performance.
With their help, it is convenient not only to remove insulation from the ends, but also to expose arbitrary areas. They can also handle various types of wires, including flat stranded, twisted pair and etc.
Price – from 800 rub.
And this is an outdated type of pliers, although still popular due to its low price and simpler design.
Among the disadvantages is a small number of functions. For example, they cannot be used to crimp wires.
Price – from 300 rub.
Well, if the store is far from you now, then this idea of making a stripper with your own hands will probably seem not only funny to you, but also useful.
The first question asked by those who previously made do with ordinary construction or even office knives is whether an electrician’s knife with a heel is really necessary to such an extent that electrical installation work cannot be performed without it? Many specialists have worked and are working without it for decades and at the same time competently perform all electrical work.
For example, some even specifically use a non-sharp knife to longitudinally cut the insulation between the cores. This method may be suitable for cables with a soft rubber or vinyl sheath. 
The heel does not provide significant savings in operating speed. Of course, the cleaning process is a little faster, but it’s impossible to say that the work is done 2 times faster, in the same amount of time. The most important factor here is the skill of the performer and his experience. A professional should be able to clean with anything, be it a construction knife or side cutters. At the same time, do it efficiently and quickly. 
Another question is that a professional must to have such a dielectric tool in your kit, but what does it give to the common man?
The most important advantages of this knife:
- comfort at work
- reliable insulation of the handle, in case someone accidentally turns on the machine and voltage appears on the cable (up to 1000 Volts)
- safe removal of insulation without “jambs”, cuts and scuffs, even if you are an amateur and are using it for the first time in your life
This knife is equally suitable for those who do both clean electrical installation work, and complex repairs, without sufficient experience in cable cutting.
Stripping GOST and TU cables
Another point that should not be forgotten is that the knife with a heel is intended primarily for flat cables type VVGng-P. Of course, craftsmen can clean anything with them, but the amenities there will be completely different. 
When stripping round cable Using such a device is dangerous. For brands like NYM, there are more convenient and specially designed tools for this purpose. 
Moreover, when using a cable made according to technical specifications(TU), and not according to GOST, the insulation will be removed faster and easier. The insulation of the cable according to GOST is much thicker, it fits more tightly to the cores and is more difficult to work with. 
Be sure to wear gloves when working here; without them, it could result in injury.
Therefore, if a knife with a heel does not remove insulation well, do not rush to be disappointed in it, maybe you just happen to have a high-quality cable.
By the way, in a similar indirect way you can find out what kind of TU or GOST cable you have. Unless, of course, you are sure that the knife is not dull, and you have tested it before on other wires. 
Let's take a closer look at the main manufacturers. They are not much different from each other, but still have their pros and cons.
Chinese red knife LS-55
Previously this knife No matter what brand it was produced under - KVT, aka a replica of the first generation Knipex, Shtok and others. Today, a similar tool can be bought at bazaars and Chinese online stores AliExpress. Other companies switched to a different design. True, some are sure that KVT and “China” are still the same thing, only KVT is twice as expensive.
Many other tools still have the shape of the handle of this knife. It is completely plastic and does not have rubberized inserts. There is a slot at the end of the handle for installing and storing a protective cover. 
It's very original and convenient solution so as not to lose it while working and not to look for it later. Other more expensive brands lack this. 
If you have a large palm, then the knife may be really small, since it has the shortest handle length among other copies. However, when working in cabinets small sizes this can be a significant advantage.
The blade is not straight and there is a slight slope. The heel is made quite well:
- teardrop-shaped
- not big
- edges are neatly processed
- good welding
One of the significant drawbacks is that you can often end up with a dull blade. With such a blade it is very difficult to make the first cut. The insulation is crumpled more than it is cut. To facilitate this process, you can use pliers, or even better, thin-nose pliers.
Crimp the end of the cable with pliers and place the heel under the outer sheath. 
The main thing is to make the initial cut, and then the knife it's already underway more quickly. It’s easier and safer to make a cut “on your own.” But when working “for himself”, he usually chews insulation. To make it easier, try bending the cable a little, making a small arc. 
Of course, it is better to purchase such a knife in person, from a real seller. At the same time, immediately check on the spot how he removes the insulation, taking a piece of cable with him.
If you get a dull specimen, you can try to sharpen it yourself. It is not recommended to sharpen electrician's knives with a heel using an engraver or a drill with an attachment. 
You can easily damage the tool and overheat the edge, especially at high speeds. It is better to use diamond files and sharpen them on sharpening stones. Of course, sharpening near the heel is not very convenient, but with skill it will work out.
The blade from the outside, which you use to cut away from you, is sharpened with any piece of wood like a chisel. And the internal one - with the help of triangular ones. If you really have no options, then you can get by with automotive sandpaper with a grit of 2500-3000. The whole thing is completed with a belt and goyim paste. 
In a similar way, you can correct and sharpen more expensive brands, the same Knipex, if it has become dull over time.
The most important advantage of this knife is its favorable ratio price quality. It is the cheapest and if you only do electrical work in your apartment or home, then this the best choice. He will work out his money 100%. The main thing is to check the sharpening. Many professionals still use such knives and have no plans to switch to knipex knives.
KVT NMI-01
Here it must be said right away that you can find a lot of knives with a similar design and handle shape. In fact, they are produced by the same plant, although they have different brand names:
Therefore, if you are thinking about buying such a knife, then you need to choose the cheapest one. The heel, blade, handle are practically no different here. 
The heel itself, due to its very large size, is not very convenient when stripping cables minimum sections- 2*1.5; 3*1.5; 2*2.5. The stripping speed also suffers from this. 
For such small wires you even have to resort to the services of a simple construction knife. The insulation is cut at the very beginning of the cable, and only then, in order not to damage the cores, it is simply torn with the effort of one hand. But the question is, why did you buy such a knife?
Moreover, not every cable can be easily broken. For example, with TU-shny, where the insulation is something like heat shrinkage, such a trick may not succeed.
It is also very important to check the quality of the weld on the heel. When stripping a rigid cable with hardened insulation, it can actually break off. 
This can happen if your heel gets caught in the cable, the knife itself tilts to the side at an angle, and you still try to remove the insulation with force. Welding it back will be problematic due to the material of the blade.
Often there is a defect in the form of asymmetry relative to the tip of the blade. It can actually be shifted to the right or left. 
Most problems with the heel are solved by grinding it down to smaller sizes and giving it a teardrop shape. Just make sure the welding is secure before doing this.
The inscription on the handle of the KVT knife is erased very quickly, which indicates the possibility of applying any name at all to this tool.
Knipex is one of the most expensive specimens. In terms of functionality, it differs little from its cheaper counterparts, but it has one thing for which you actually overpay - its branding.
When buying any of the knives, at first glance it is not immediately possible to distinguish which brand is in front of you. When purchasing Knipex, you will immediately understand that this is the one in front of you. The style and design makes itself felt and is difficult to confuse with others.
This tool has very little defects and you can work with such a knife long years. You cannot find the grossest defects inherent in other manufacturers. The heel is always welded evenly and securely. 
Convenient teardrop shape. It is to its size and shape that all other brands are adjusted when they are going to modify them. Even if any mistakes are discovered, it is easiest to exchange the Knipex tool from official suppliers. 
The only inconvenience may be caused by the blade, which will eventually become dull. Especially if you use it to cut insulation like construction knives. 
You can fix it using the methods described above. After which, he will again serve you faithfully.
True, certain problems may arise due to the shape of the knife. Initially, the bead on the handle will interfere, but if desired, it can be ground off a little. 
But the most difficult thing is plastic protection blade, which is located on top and prevents you from maintaining the factory angle. If you need this protection, you will have to change the angle a little. This will not stop the knife from cutting, the main thing is that the blade is sharp. If you want to keep the “factory settings”, you can grind off a couple of millimeters of plastic. 
Most often it goes bad outer side blades, the one that is intended for stripping away from oneself. This is due to the fact that if you work carelessly inside electrical panels, the knife can break off and hit some obstacle with this side. 
Well, in general, this best knife electrician from all presented, especially for stripping rigid and GOST cables.
The design shape is very similar to the KVT NMI-01, but slightly smaller in size. When purchasing not in person in a store, but through the mail by parcel, you may encounter problems:
Therefore, with this brand you need to rely more on luck. There are no guarantees whether you will be lucky or not with quality. And the price is twice as high as that of a red Chinese knife.
The main difference here is the original handle. Namely, its curved shape and special indentations for fingers. If you have worked with other brands before, you will feel discomfort at first. It's a matter of habit here.
The handle is quite long and it is not very convenient to use it in narrow and compact cabinets. Unfortunately, there are no company inscriptions indicating the manufacturer's brand. You can easily run into some kind of fake, where any Chinese will write Made in Germany. 
The heel, like the Knipex knife, has a slope and is small in size. This makes it easier to work with small cross-section cables. But the quality of the steel raises questions. Jagged edges may appear if the blade hits the copper core of the cable during the stripping process. 
But for the money, taking into account the German manufacturer, this is not a bad choice for a quality knife.
The knife has a simple and uncomplicated shape. This type of handle is very common in Weicon, Haupa and some NWS. Made of homogeneous material, without comfortable rubberized inserts.
Has a huge cap protecting the blade. The heel is of an original shape and medium in size, and also has a slope. It is boat-shaped and raised at the ends. 
Made so that it can be cut into the insulation right from the middle of the cable. Sometimes this is simply necessary. 
It removes insulation similarly to other knives and at the same time has a price tag that is several times more expensive, often even more than that of Knipex. It's up to you to decide whether it's worth paying extra money. When you have a choice, you can look at more attractive design models.
COMPARISON TABLE
| Brand | Heel | Pen | Price |
|---|---|---|---|
| Red LS-55 | Small | Plastic | 300 rubles |
| KVT NMI-01 | Big | Two-component | 1000 rubles |
| Knipex KN 9855 | Small | Two-component | 3100 rubles |
| Sata | Big | Two-component | 800 rubles |