Electrician's knife: advantages of working with the device, its functions; review of popular models

The electrician's knife, equipped with a special heel, is designed to strip insulation when cutting wires. Many people buy devices in hardware stores, but their cost is quite high, so you should think about the advisability of such waste. When it comes to a craftsman who works with wires every day, then such an acquisition is justified. If you need to carry out one-time manipulations, it is better to make the device yourself.

Device functions and applications

The device for removing the insulating layer of the wire is narrowly focused, it is not used for other purposes, but its practicality prompts the master to acquire such a device. The heel knife is simple but effective:

• the blade is necessary for cutting the rubber or polyvinyl chloride coating;
• the heel prevents damage to the wires inside and acts as a stop for the depth of the notch;
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• a special handle is needed for the convenience of positioning the device in the hand.

A knife with a heel is able to cope with the coating of ordinary conductors, but the device is not suitable for working with steel tapes on armored cables.

In addition, much depends on the size of the heel: the wide one is convenient to work with soft sheaths of conductors, but difficult with wires of small cross-section; the narrow one is useful for stripping wires with rigid cores.

Therefore, when choosing, it is necessary to be guided by the basic conditions of the master's work.

The products are equipped with a double-sided blade, so you can cut the casing in a direction convenient for a specialist - both from yourself and towards yourself. Working with a knife is carried out as follows:

• The heel protrusion is located under the insulating layer to be removed so that the bottom plane is above the conductive core.
• With longitudinal movements, the device is moved to the required distance, while the base of the heel slides along the conductor without damaging it due to its own smooth surface.
• After making an incision of the desired length, the knife is removed, the conductors are freed from the outer sheath, which is removed using a cutting edge on the blade.

Precautionary measures

The product cannot be classified as a piercing object, but the cutting edge may harm the wearer during handling or transportation. That is why, while wearing, it is advisable to cover the working part with a special protective casing. The latter will also protect the device from mechanical damage and dullness when hitting other tools.

It should be noted that the handle of most devices is made of special dielectric material. However, this does not mean that you can work with the power on. Most manufacturers indicate the maximum allowable voltage on devices, which is often no more than 1000 V.

Even a novice master can do these manipulations.

To work with the device, no training or specific skills are required, you just need to follow basic safety measures.

Review of popular models

Today, various types of products can be purchased at specialized retail outlets. Often they practically do not differ from each other, but still have their own advantages and disadvantages.

China-made device

Previously, such knives were produced under the name KBT, they were analogous to Knipex. Today, the tool is manufactured under the LS-55 brand and can be purchased on the market or in AliExpress in China.

The device is equipped with a fully plastic handle, without rubberized inserts. At the end there is a slit for inserting a protective cover. This is very convenient so that you do not need to look for a part after work. This function is sorely lacking in more expensive models.

Compared to similar devices, the Chinese product has a small handle, which is not very comfortable if a person has a large palm. But when carrying out manipulations in small lockers, this is very convenient, the heel is made with high quality:

• has a teardrop shape;
• small size;
• the edges are processed very neatly;
• high quality welding.

A significant drawback is that blunt blades are often encountered. It is difficult to make a primary cut with such a device, because the insulating film is not cut, but crumpled. To facilitate the procedure, you can resort to using pliers. The latter are needed to securely fix the cable and slightly press on it, lifting the outer insulating layer.

Then gently slide the heel under the guide sheath. The first cut is important, but in the process of work it will be easier. It is much more convenient and safer to cut the casing from the "away from you" position. It is better to purchase the device locally, so that the device can be felt and tested in action. If the product turns out to be dull, you can try to sharpen it.

For these purposes, it is undesirable to use an engraver or drill. It is best to use diamond files. It is more convenient to sharpen the outer surface with chisels, the inner one - with triangular bars. If there are no such devices, in extreme cases it is permissible to use sandpaper. Similarly, you can sharpen expensive devices that have the ability to dull over time.

The main advantage of this device is the optimal price-quality ratio. This is the most budgetary product, if local work is coming in your house or apartment - this is the best option. Even some experienced specialists, wanting to save money, use such knives.

KBT NMI-01

There are many different models with this design and shape of the handle. In fact, they are produced by one plant, but under different brands - KBT, Neo, Haupa, Stock. If you want to buy such a device, you should choose the cheapest one, because they are practically no different.

The heel is large, but this is not always convenient when stripping small conductors. For these purposes, craftsmen have to use an ordinary construction knife. The insulation is cut at the beginning of the cable and then torn apart by hand.

It is important to pay attention to the quality of the weld used to secure the heel. It may break when stripping rigid conductors. This occurs when the heel is trapped in the guide wire and the device is tilted to the side at an angle. Welding the part back on is not easy due to the blade material. Very often there are defective devices with an asymmetrical blade that moves to the right or left.

Many craftsmen solve the problem of an uncomfortable heel by reducing it using the stitching method. Before carrying out the manipulations, you need to make sure the quality of the welding.

Knipex KN 9855

The device is considered one of the most expensive, although it does not differ much from its counterparts. One of the main criteria for high value is the brand. When buying any product, it is difficult to name its brand at first glance. By purchasing Knipex, you can immediately see that it is he, because the design and style are difficult to confuse with others.

Devices are rarely defective, they often function for many years. It is rare to find large defects, which are many from other manufacturers. The heel is level and firmly fixed, made in the form of a drop.

The only drawback is the blade, which will become dull in the process, especially if you cut off the insulation of the cores. But it was stated above that the devices can be sharpened without difficulty, so it will again be like new. A significant disadvantage is the plastic blade protection, which is located at the top and prevents the preservation of the factory angle. If protection is necessary during operation, the angle should be slightly adjusted. The device will not stop performing its functions, the main thing is the sharpness of the blade.

Very often the outer side of the blade, which is used for stripping "from oneself", deteriorates. This is due to careless work inside electrical panels, when the knife may fall and hit this side. In general, this device is considered the best among experienced craftsmen, especially if you have to work with rigid and GOST conductors.

DIY making

A knife for removing an insulating layer is a convenient and useful device, but due to the high price it is not always available to people who cut wires periodically. In this case, you should not neglect the opportunity to become the owner of such a device and make it yourself at home.

There are several methods with which you can make a knife with your own hands. Some of them:

• using a blade from a stationery knife;
• metal strip application.

In these two ways, you can make a quality product. It is necessary to choose depending on the availability of tools that are needed for the job.

Using a utility knife blade

The blades can be purchased separately or complete with a knife. Two parts are required to work. Step by step process:

1. Cut a ledge at the end of one blade, on which the heel will be fixed. Drill holes with a diamond disc or drill.
2. If you plan to make a device that will cut the insulating layer in two directions, you should also sharpen the second side of the protrusion.
3. From the second part, cut a piece from which to make a heel with a slot. The size of the latter must match the length of the protrusion on the first part.
4. Insert a ledge into the slot of the heel, then make high-quality soldering with a soldering iron and lead-tin solder. The parts must be securely connected to each other.
5. File the heel with a file until it becomes the correct oval shape. In addition, the soldering area must be carefully sanded.
6. After carrying out the manipulations, a handle should be made. To do this, you can use plastic or plywood: you should cut out two pads, which are fixed on the blade with epoxy glue.

The resulting device is not suitable for use as a professional tool, but for household needs it is the best option.

The disadvantage of this method is the impossibility of making a curved blade, like in factory models.

To make such a product, you do not need a special tool and special skills in working with a soldering iron. In addition, the work piece can be shaped to any desired shape. Taking into account that the device must be quite durable, be sharpened and have the property of keeping sharpness edges, it is advisable to use high-alloy carbon steel for the workpiece, the optimal width of which is 3-5 mm. Step-by-step instructions:

1. On a metal strip, mark the shape of the future product, taking into account the length of the heel. Then cut off the excess parts with a grinder.
2. With the same tool, reduce the thickness of the metal in the area of ​​the future blade. After this procedure, the heel begins to differ from the base in length and width.
3. Sharpen and grind the crescent-shaped part of the device on both sides.
4. Be sure to sand the heel. It should be noted that the quality and functionality of the device, the safety of the insulating layer of conductive conductors, depend on the smoothness of the surface below.
5. The handle can be made of plastic, wood, or a piece of hose, which must be pulled over the back of the workpiece and sealed in a heat shrink tube.
6. At first glance, this method seems more laborious, but the result is a strong, flexible and durable fixture.

An electrician's knife with a heel is a necessary and functional device with which it is very easy to clean conductors from insulation. When choosing a product, it is necessary to build on the expected loads on it. In addition, the device can be easily made by hand, which can significantly save money.