Universal press tongs for crimping ferrules. What are wire crimping pliers and where are they used. For crimping non-insulated cable lugs

Crimping a wire cable is a very responsible task, especially if this connection is a power one. In this article, we will look at how to properly terminate the connection of low-current wires (up to 15–20 amperes).

Remember! The use of power wires and lugs of the wrong material and size can lead to serious consequences, such as a fire on the wiring, for example.

So, how to crimp the wires with lugs

In addition to selecting the necessary wires and lugs, this task will require special tool, which is called "crimper" or press tongs.

Outwardly, the tool is very reminiscent of pliers, at the ends of which a special matrix is installed, into which the tips and the non-insulated part of the cable are inserted.

This tool is designed to provide an even ferrule force around the wire, eliminating poor contact when crimping the cable. In addition, there are universal tools, allowing not only to crimp, but also to cut the cable, remove insulation from it and twist the core.

Particular attention should be paid to the type of cable, in living conditions power cable can be of two types:

with a monolithic core;
stranded.

When crimping a wire with a monolithic core, it is enough to remove the insulation layer with a small margin (up to 0.3–0.5 cm), (using a tool or using a knife to strip the insulation), then straighten and degrease the area to be worked on, after which you should put on on the heat-insulating tube.

Then, select on the tool (with a jumper in the matrix) a certain section and tip type. After carrying out the above manipulations, it is necessary to insert the prepared end of the wire into the tip, after making sure that there are no cracks in it.

Install the ratchet lock lever. Failure to comply with this paragraph threatens with poor-quality crimping of the tip and, accordingly, poor quality connections.

The final part of crimping a wire with a solid core with a tool:

make sure the connection is correct;
insert the tip all the way into the device so that the numbers with the matrix marking are knocked out on the front or back sides of the tip;
to the end we sink the bare section of the wire into the tip;
as soon as the operation is completed, the handles will automatically begin to return to their original position (for this, it is necessary to transfer the ratchet lock lever to the “locked” state);
the end of the cord is done, the final step is to put on a heat-shrink braid at the junction and warm it up with a special hair dryer or a lighter.

If the handles do not return to their original position, then this problem may be caused due to the following problems:

too weak grip tool handles;
malfunction of the ratchet mechanism;
"weak" spring in the ratchet;
ratchet lock lever not fully installed.

If you have to terminate stranded wires, then the above method should not be used, as it has many nuances.

Therefore, the wires large quantity cores are crimped according to the following instructions:

After the above manipulations, the cable processing can be considered complete.

set the required section and tip type in the device matrix;
install the tip all the way into the device so that the numbers with the matrix marking are on the front or back sides of the tip;
we fill the straightened cable cores into the lug until it stops ( Attention! It is forbidden to twist the cable cores);
applying force, press the handles of the crimper;
the crimping of the stranded wire is completed, now we return the heat shrink that was previously put on the cord to the junction and warm it up building hair dryer, soldering iron or turbo lighter;
after performing the operation, the handles should return to the standard (unclenched position), if this did not happen, then the problems described above may be the reason for this.

How to crimp cable lugs without a tool

From the point of view of construction technology, crimping wires without an appropriate tool is prohibited, the only exception is rough installation to check the work performed.
However, for any domestic work with low-current consumers, work without a crimping tool is allowed.

There are several methods for terminating cords without tools:

Tip soldering

For soldering, of course, you do not need serious and expensive press tongs / crimpers, but the following “household” repair tools should be present in your arsenal:

Soldering iron (from 80 W) / blowtorch / gas burner.
Soldering kit (fluxes / rosin, solders of various types).
Heat shrink tubing and/or electrical tape.
Basic knowledge and skills of working with a soldering iron.

The algorithm of actions is as follows:

Crimping with core/hammer

This method has many disadvantages, the main of which is insufficient clamping, which can be fraught with heating of such a joint. However, it is often practiced, especially in cases where the connection will not work with high-current devices.

For this method minimum tools required:

A hammer.
Kern (optional, but desirable).
Small file for metal.
Vise (optional, but desirable).
Conductive paste (highly desirable).
Electrical tape and/or heat shrink.

To end with these tools, we proceed as follows:

Related videos

When crimping conductors, one of the main conditions for obtaining high-quality contact and its reliable operation in the future is the use of professional tool. One of these tools are press tongs or crimpers designed for crimping sleeve, insulated, not insulated tips and automotive terminals.

Crimpers for automotive terminals and insulated lugs must have dies with a double-circuit crimping profile - along the core and along the insulation. Also, its geometry and shape must match the crimp part of the ferrule.

As a rule, it is best to buy sets at once, where the pliers themselves and all the necessary matrices are included.

Among domestic manufacturers stands out the company KBT and its two sets for crimping:

Consider their configuration, differences and principles of operation. Both of these sets are designed to crimp both insulated and non-insulated ferrules.

Press tongs CTB

The CTB set includes:

press pliers themselves
five numbered matrices
plastic case

Press tongs have a mechanism for quick removal and replacement of dies.

Keep in mind that any matrix, like any part, has a run-in property. And during the first few dozen crimp cycles, it is quite possible that the tip may bite.

Sometimes the jam is such that the matrix jumps out of its quick-release mechanism. This does not at all mean a poor-quality tool, and over time, after running in, you will forget about such an inconvenience.

Actually, quick-detachable matrices are of course positive moment, but in practice there is really a lack of some mechanism for their rigid fixation. And the longer you operate the crimper, the more this mechanism is weakened.

Press tongs CTB are made of high quality steel. Equipped with a ratchet mechanism that provides a full cycle of crimping. There is also an asterisk with which you can adjust the clamping force.

In the upper part there is a lever that allows you to unlock the tool from any position.
If you choose the wrong die size and start crimping, the press tongs may not reach the very end, thereby locking the handles in an intermediate position. Here, just the same, you will need an unlock lever.

The handles are elongated, so that it is convenient to crimp with two hands. For relatively large sections and large volume work is very helpful.

Compared to other manufacturers, a small angle of opening of KBT crimper handles plays a significant role. For other models, in order to perform a girth, sometimes you need to have not hands, but large paws. A small angle of wiring allows you to use the tool with much greater convenience and comfort.

Matrices for press tongs

Why do we need as many as 5 sets of matrices? There is not only a difference in the cross section of the crimped lugs, but also in their functionality and size.

For each type of tips, you can choose your ideal option.
In the CTB press tongs, as in the CTF, the dies are interchangeable, which makes these sets absolutely compatible and can significantly save your budget.

Most often, you have to use dies designed for crimping insulated and non-insulated sleeve lugs of the NShVI and NShV brands. The matrix is digitally marked along the cross section of the tip.

These dies are specially designed to form a solid pin at the end of a stranded strand.

To give mechanical strength a special corrugation is applied on the inner surface of the crimping profile.

The MPK-02 model matrix fits the most popular series ferrules section from 0.25 to 6mm2.
And what to do if you have a sleeve end with a cross section of as much as 25mm2? Here you will be rescued by the matrix of the MPK-03 model. This die already crimps insulated and non-insulated ferrules from 10 to 25mm2.

For crimping double end sleeves of the NShVI-2 brand, you need to use the MPK-06 matrix. It has 7 positions and crimps ferrules from 0.5 to 6mm2.

Keep in mind that it does not come with the tool and you will have to buy it separately. You can get acquainted with the current prices and choose a set of matrices for yourself.

There is another way out of the situation. If you need to crimp the double tip of NShVI-2, and there is no way to buy a matrix for it, use the ordinary MPK-02 matrix.

The only condition is that you need to crimp such a NShVI-2 with a connector one size larger.

That is, when you have a double tip with a section of 4mm2 NShVI (2) -4-12, then you need to press it with a matrix designed for a single one under 6mm2.

The set also includes an MPK-01 matrix for insulated connectors of the brand NKI, NVI and the like. It is designed for sections from 0.5 to 6 mm2.

Well, the last two sets of matrices are MPK-04 - for auto-terminals and MPK-05 - for bare copper tips.

The dies are inserted into the pliers in such a way that the side of the die with the smallest section of the crimping profile is always located at the edge of the jaws.

Sleeve tips NShVI this crimper compresses with a trapezoid. Such a crimp profile is quite wide and may cause some connection problems with individual equipment. Keep in mind that when connecting wires to starters of the second magnitude, after crimping wires of relatively large sections with a trapezoid, sometimes you have to put them into contacts sideways.

Press tongs set CTF

This set also includes 5 matrices. True, there is no longer a quick release mechanism.
To replace the matrix, you will have to use a hex key. Which is not very convenient and can take much longer than the compression process itself.

Of course, you can do amateur activities and somewhat modernize the process of removing matrices. To do this, nuts can be soldered onto the factory screws, which are already easy to twist by hand without the use of hexagons and special keys.

Also included are 2 spare screws from the dies in case you lose the current one or ruin the threads on them.

The lack of a quick release mechanism is of course one of the main disadvantages of this tool. Imagine you are sitting in front of a closet, in which there are a couple of hundred conductors. They all go in order different section and standard sizes and they need to be crimped accordingly. How much extra time and nerves it will take you to unscrew and twist the matrices, the question is far from rhetorical.

When inserting dies into CTF pliers, in order not to be mistaken, look at the size of the crimping slot. big size insert in the direction of the handles, with a smaller one - in the groan of the nose of the tool. The vertical positioning of the matrices also plays a role.

A reasonable question arises, why do we need a CTF set with an inconvenient process for replacing dies, if there is a CTB press tongs with a quick release mechanism?

The fundamental difference of CTF is the parallel closure of matrices. This form of crimping is the most important advantage over any other pressing tongs.

When using conventional press tongs, the crimping of insulated and non-insulated ferrules first occurs from one edge, then in the center, and only at the end the ferrule is crimped in its entirety.

But the CTF model has such a design that the jaws on it close in parallel from top to bottom. Therefore, crimping occurs evenly and immediately over the entire surface of the tip.

Parallel closure of matrices provides more high quality connections.

True, it is possible that you have chosen the matrix and the tip, it seems to be correct, and the wire after crimping is still poorly clamped inside the sleeve. How is this possible?

And the reason here lies in an unscrupulous cable manufacturer. It is they who can make the wire, relying on their specifications, and not on GOST. As a result, the cross section is not 1.5 mm2, but less than 1.25-1.3 mm2. You, however, clamping it all with a 1.5mm2 matrix, naturally cannot achieve the result you need.

On new pliers, nothing needs to be adjusted. The factory settings are set optimal conditions crimping. However, during long-term operation, the matrices can become loose and play and slack appear.

Adjustment is carried out using an eccentric. Unscrew the stopper screw and turn the sprocket. To the plus side, if you need to increase the convergence of the matrices and to the minus side, if, on the contrary, to weaken.

The manufacturer KBT for its crimpers says that it guarantees crimping of lugs in 30,000 cycles without loss of crimping quality.

Also ctf pliers have:

unlocking mechanism from any position

handle lock button

By the way, the handles here are no longer elongated and it’s no longer possible to comfortably grab them with both hands.

Why do you need to fix the handles? Imagine that you are standing on a stepladder and, under the ceiling, are crimping the handpiece sleeve in the junction box with one hand. You need to put it on the wire, put it in the right slot of the matrix and fix it before finally pressing it.

It will be problematic to do this in one go due to the uncomfortable position and cramped working conditions. Here, just the same, the fixing mechanism is indispensable. They inserted the sleeve, tightened it, intercepted it and squeezed it properly.

It is not recommended to crimp solid wires with CTB and CTF press pliers. To do this, you need to apply more effort and the ratchet mechanism must be designed for this. In this case, it is better to use other brands of tools from KBT. For example, a crimper - PK-16u and PK-35u.

In general, both sets of CTB and CTF can complement each other and be indispensable assistants when crimping sleeve insulated, non-insulated and other types of thin-walled sleeves and tips.

Of course, it is quite enough for the master of the station wagon to have one of them. However, remember that versatility doesn't always pay off. It is much more reliable to have a set of exactly tongs, and not a set of matrices for one press tongs.

Sets of press tongs CTF and CTB in online stores can be purchased within 5000 rubles.
The pliers themselves with only one matrix will cost at least two times cheaper. Choose for yourself required option can .

The key to any quality electrical connection is the area of \u200b\u200bcontact of the wires - the larger it is, the more reliable the contact. Of course, all this is selected relative to the cross section of the connected wires, so the main thing here is to do without fanaticism. If the first connections of this type were long twists crimped with pliers, now they are straight wires that are fastened together by crimping pliers inside a special crimping sleeve. The disadvantage of this connection method is the need to have a crimping tool and consumables in the form of bushings or lugs, but this is fully offset by an increase in the speed of work and an improvement in its quality.

Where are crimping pliers used?

Regardless of the size of the crimper, it has only two main uses - the preparation of current-carrying conductors for fixing them to the terminals of sockets, switches and other electrical appliances, as well as the connection of several wires to each other.

In the first case, crimping is justified if stranded wires are used. If they are clamped into the contact terminals without preparation, then over time, under the influence of an electric current (it creates microvibration), the veins will “shrink”, free space will appear between them and the contact will generally weaken.

This is one of the reasons why it is advised to use solid wires for laying power wiring, but with the spread of crimping devices for wire lugs, this recommendation has lost its meaning.

Crimping is also used when working with large-section cables - it was used even long before the advent of "household" devices. True, a high-quality connection can only be obtained using a special press for crimping cable lugs, which even now is far from being pocket-sized. To create the necessary force, such devices use the principle of a jack or a separate hydraulic drive - human force, even applied through a conventional lever, is not enough to compress a thick cable with high quality. An example of such a device in the video:

It will be useful to crimp and, if necessary, connect two or more wires. In this case, they are assembled together, a sleeve is put on them and crimped. In this case, the wires can be inserted into the sleeve both from one side and from both sides: in the first case, a kind of twist is obtained, and in the second - a coupling.

The advantage of this type of fastening is that after crimping, air does not penetrate into the sleeve - in fact, a tight connection is obtained. This allows you to connect in this way even copper and aluminum wires, the contact between which, under normal conditions, oxidizes over time.

Varieties of crimping pliers

Structurally, crimping pliers are divided into two main types - operating on the principle of pliers or diaphragm.

The first of them are more common - they perform squeezing only from two sides, but unlike pasatages, they have cutouts in the jaws. special form that act as guides. This allows you to perform high-quality fastening on the wire core of the lugs, the base of which in the cross section has a "P"-shaped shape.

On video different kinds wire crimping tools:

The advantage of such devices that crimp wire cores is their relative versatility - they can “get close” to the tips from any side. The main drawback lies in the need to have several such pliers “on hand”, since cutouts for 3-4 cartridge sizes are usually placed on the jaws. As an option, you can purchase a universal crimping crimper with interchangeable dies, which are mounted on a special cassette. If you need to work with other types of tips, the old ones snap into place in the cassette and suitable ones are selected in their place.

Diaphragm devices can crimp sleeves from four or six sides - depending on the diaphragm mechanism. Due to the full girth of them, a better and tighter crimping of the end of the cable is performed, and the device automatically adjusts to any thickness of the sleeve.

Before choosing such a tool, one must take into account its main drawback - you can only crimp a sleeve into which the wires are inserted on one side - otherwise the pliers will remain on the wire, since their head is closed.

A somewhat separate category are crimpers that crimp a computer cable such as "twisted pair" and the like. The principle of operation of such a tool is the same as that of two-jaw pliers, but instead of iron or copper bushings, their matrices are "sharpened" to work with plugs for computers or telephones. Here, it is not crimping as such, but the displacement of contacts that cut through the insulation of the wires and tightly pressed against their cores.

How to work with crimping pliers - important nuances

The process of crimping wires is intuitive - the sleeve or tip is put on the wire(s), a matrix of tongs is supplied to it, the tool handles are closed and the contact is ready. In practice, most often the “first pancake”, or even several, turn out to be “lumpy”, and practically in literally– Connections may be far from ideal. There have also been cases when, in a seemingly well-compressed wire, contact deteriorated over time.

If the shape of the terminals is not maintained

In the first case, the squeezing force settings of the matrix parts are to blame, which can be different for both individual wires and the tips themselves. Because of this, professionals prefer to have at least two tools to avoid having to reconfigure the spring to work with different wires or sleeves.

The quality of work is also affected by the material from which the sleeves are made and their thickness. Tight terminals are always much easier to crimp and hold their shape better than those made of soft materials.

The correct orientation of tips with a “P”-shaped section is, although lying on the surface, but often ignored requirement, and after all, the misalignment of parts in any mechanism does not always fall into the zone of permissible error.

Twisting stranded conductors before crimping

For every experienced electrician who started with twisting and soldering wires, this movement is most likely already a reflex, but when crimping for multi-wire lugs, it must be disposed of. The validity of this statement can be verified by simple experience - take a pair of single-core single-wire wires, place them crosswise and squeeze with pliers. In some cases, both wires are deformed, and sometimes only one, but at the same time it will be almost completely broken and will hang out on a thin isthmus. Of course, the conductivity of this vein will decrease significantly.

If the wires do not twist, then when the tip is crimped, they will be located parallel to each other and, when deformed, they will simply fill all the voids without crushing each other.

The nuances of wire sleeves on the video:

Color marking of sleeves and matrices

Different sizes of sleeves some manufacturers mark individual colors and the same labels are applied to matrices of ticks.

It must be remembered that unified system it has not yet been developed for this, so if you purchase sleeves focusing only on color, you can get consumables that are not quite suitable.

As a result - what to choose

Crimping pliers are very subject to the rule that each job needs its own tool, only here everything is a little more complicated, since a separate device is by and large needed for each type of wire used, if you do not want to mess with adjusting the spring force. Therefore, what specific tool is needed and in what quantity can only be decided on the basis of everyday work tasks.

Content:

For high-quality connection of contacts of devices, equipment, crimping of the ends of the cable and wires that are connected to them is used in electrical engineering - this method gives an excellent connection of conductive surfaces. In order to use crimping, you need lugs or sleeves that have different kind and appointment. The crimping method requires a special tool. Consider what tips are and how they are crimped.

Types of tips for crimping

For every inhabitant, a striking example of improper wiring is the stair switchboard, many apartment owners have melted wires in the switchboard, there are twists. Ferrules for wires for crimping can save citizens from the possibility of heating and ignition electrical wiring as a result of poor-quality wire contact, the absence of cable lugs.

When there is good contact between the cable or wire being connected and the connection device, the transition resistance is minimized, and with an increase in current load on the contact group, they can heat up in case of poor contact. Sleeves and tips are intended to remove or minimize the contact resistance, in other words, to exclude poor-quality contact, for a bolt or screw.

For crimping (crimping for lugs) of wires and cables, special products are used - lugs and sleeves. Tips can be stranded wires and single-core wire, they are subdivided according to the purpose and type of wire for which they are used (copper or aluminum).

For crimping the copper conductors of the cable, lugs made of seamless copper tube, which is flattened on one side and has a hole for a screw connection. This type of tips happens:

With different diameters for a wire and a mounting hole that does not have protective coating;
for crimping electrolytic tinned with different holes for fastening.

The marking of this type of tips is as follows:

uncoated, TM - X - Y, where X is the cross section of the wire, Y is the size of the hole for fastening;
coated, TML-X-U.

There is another type of lugs with a control window, these are tinned copper products for terminating cable and wire cores. A feature of this type is the ability of the termination performer to control the correctness of crimping through the control window. This type of product is marked as TML (o), it is noteworthy that they can be installed on the ends of cables using solder and soldering, which almost completely removes the value contact resistance.

Quite often in electrical engineering there is a connection aluminum wire with a copper cable, in this case it is recommended to use aluminum-copper lugs for high-quality connection of the aluminum wire and the shield copper bus.

Decreasing overall dimensions devices and devices, pin products have become popular tips for ending. They are used in electrical equipment and circuit breakers in protection devices. With the reduction of clamping fasteners, the pin is the most optimal solution for good contact. This species is marked as NSHP.

Tips NShVI

Cable lugs for crimping NShVI are a pin sleeve product with insulation. Electrolytic copper is the material from which it is made, insulation is installed on the back side, which is thicker than the metal part. When the terminated wire is inserted into the socket with this lug, only its insulated part remains under the clamp. In industry and in everyday life, this type of lugs is used for cables up to 35 sq. mm in cross section, they are pressed with a special tool.

There are several modifications of this tip, which differ in the number of wires connected in one tip. For two cables, the marking has the form NShVI2, there are no structural differences in this lug, the same metal part and PVC cuff, but the diameter of the sleeve (skirt) is larger, designed for two wires.

Features of working with NSHVI

Cable lugs of this type are intended only for multi-core cables, they cannot be used in the termination of wires with one core. For rigid (single-core) wires, crimping is used with bushings (sleeves) without insulation. Crimping of stranded wire is carried out as follows:

the wire section is selected, the brand of the tip is selected, into which the cores must enter freely and tightly from the side of the skirt;
in practice, the type of tip is selected with some margin. Example: PV-3 wire with a cross section of 1.25 sq. mm can be terminated with a tip from 1.5 sq. mm. Skirt section - up to 2.5 sq. mm.

Tool

Crimping of cable lugs is carried out with a special tool that is designed and manufactured for this purpose. A tool is necessary for crimping the lugs, since a person with a simple effort cannot create the necessary force for high-quality termination of the cable core. Which crimping tool to choose depends on the cross-section of the wire or cable that is being worked on. We list the most used tool:

Press tongs brand PK2 or PK2M are hand tool, which is used in the termination of conductors of wires and cables with a cross section of up to 10 sq. Mm.
Press tongs of the PK1 or PK1M brand are a reinforced version of manual tongs with long handles, they can make the end of lived up to 50 sq. mm.
Tongs are hydraulic, manual, which without much effort can terminate the core up to 10 sq. mm.
Hand press, which is used in industrial production for a wire with a section up to 240 sq. mm.
Hydraulic press with electric drive or foot pedal, cable ends up to 300 sq.mm.

Crimping sleeves

Not in every device or device, switching an external circuit uses cable lug, there is also a sleeve ending, its choice is made according to the type of connected wire (copper, aluminum). For cables with copper conductors - marking of sleeves GML, where:

G - product name, sleeve;
M - the material from which it is made, copper;
L - the product has a coating, tinned.

For aluminum wires GAO brand is selected: aluminum sleeve closed type. When it is necessary to make a connection with the transition of aluminum to copper, a product made of an alloy is selected. It is not allowed to use products for copper wires on aluminum conductors, this is a heat couple that will heat up due to the electrochemical reaction that takes place in the material of these conductors when connected.

Preparing for pressing

You can’t just put a cable tip on a core, you need to perform a number of preparatory steps:

clean the desired length of the end of the wire or cable from insulation - you can use a special tool, a stripper;
we twist the cores by hand and insert them from the side of the skirt into the tip;
first, the tip is selected according to the cross section of the core, observing the conditions for free and tight entry into the tip sleeve.

Crimping of wires with tips is carried out with a special tool. On each press there is a marking of matrices and the main part according to the type of tip or the cross section of the core. Now the color standard is observed, for this reason it is easy to combine the section and the matrix in the desired position.

How to crimp a wire

In the event that you have not previously crimped cable cores, you need to practice on unnecessary pieces of wire or cable. To obtain a high-quality connection, you must adhere to the developed rules:

The cable inserted into the sleeve (sleeve with a flare) of the tip must be held by hand in the socket.
After making sure that the matrix matches the selected tip, you can begin to squeeze the handles of the press until the ratchet mechanism is activated and an audible click.
The ratchet mechanism of the press simplifies the pressing process. The mechanism does not allow the press to unclench, and when the wire is crimped unsuccessfully, it must be unlocked.
Double-circuit crimping compresses the insulated part of the ferrule and the metal contact. Such a matrix has two sockets, they are different in size, so you need to carefully look so that the cuff fits into its socket, and the metal contact of the tip into its own.

Conclusion

Each tip must correspond to the wire, most common mistake in crimping cable cores, it consists in a mismatch between the selected tip and the material of the wire; you should not put on a too loose sleeve on the wire. Do not use products large diameter for termination of conductors of a smaller cross section, this can lead to an increase in contact resistance and heating of the contact. You can not cut the sleeve into two parts in order to save products, do not use homemade tips.

For high-quality crimping of cable cores, it is necessary to use a special tool, a chisel and a hammer will not be able to make the necessary crimping, to give high-quality contact.

Modern electrical engineering is constantly being improved, including in the field of connecting wires and cables for various purposes, power and conductivity. The quality of the wiring largely depends on how well the leading wires and their contacts are prepared. They must be crimped in a certain way, and this task is completely solved by special pliers for crimping wire lugs. They are widely used among electricians. Using the tool, not only ordinary cables are crimped, but also various connectors used in non-standard connectors.

Application of crimping pliers

All pressing tongs, regardless of their size, are designed to perform two main tasks. In the first case, several wires are securely fixed to each other, and in the second case, current-carrying wires are prepared for their subsequent fastening in the terminals of various electrical devices.

First of all, crimping is required when connecting stranded wires. If they are inserted into the contact terminals unprepared, then gradually under the influence of microvibrations created electric shock, individual cores will be compacted. A free space is formed between them, and therefore the contact will become much weaker. For this reason, power wiring was previously always laid with single-core wires. However, after press tongs appeared, this recommendation has lost its relevance.

The connection of cables of large cross-section by crimping has been used since ancient times, when household tools was not there yet. The quality of such operations was ensured by the use of special powerful presses capable of creating the necessary force. These devices operate on the principle of a jack, and many of them have a separate hydraulic drive. With the help of such presses, even the thickest cables are reliably connected.

The crimping method has proven itself well when connecting two or more wires. For this purpose, crimping pliers and wires are used. A special sleeve is put on their ends, assembled together, after which they are crimped. Depending on the type of connection, the wires are inserted from one or both sides of the sleeve. The first option allows you to get reliable twisting, and the second - high-quality.

The main types and varieties of ticks

Structurally everything crimping pliers- crimpers can be of two types. The former work as, and the latter are diaphragmatic. The first option is the most widely used. In this case, compression is performed only from two sides. The main difference from pliers are special-shaped cutouts located in the jaws. They act as guides and provide high-quality fastening of the tips on the wire core.

Such crimping pliers are considered universal to a certain extent, since they can grip the tips from all sides. The main disadvantage of such pliers is the presence on the sponges of only 3-4 cutouts under different sizes sleeves Therefore, during the work you have to use several tools. Most the best option the use of a universal crimper is considered, which includes interchangeable dies fixed on a special cassette. In order to crimp the wire, the most suitable tip is selected, and the unnecessary one is inserted into the cassette in its place and fixed.

Diaphragm pliers can be used to crimp four or six sides, depending on the design of the operating mechanism. Full wrapping on all sides allows for the tightest crimping of cable ends. During operation, the pliers are automatically adjusted to a specific sleeve diameter. The main disadvantage of such a tool is the possibility of crimping sleeves only on one side due to the closed head.

AT separate category it is possible to include crimpers designed for crimping computer cables. They work in the same way as double-jaw pliers, with the exception of the matrices themselves, which have a specific configuration for computer and telephone plugs. In this case, the essence of crimping is to shift the contacts that cut through the insulation of the wire and are tightly pressed against its cores.

Depending on the destination, all crimping Tools is divided into the following categories:

Removal of insulation and sheath from wires and cables. With these pliers, a section of insulation is cut off without damaging the cores. They can be customized to desired diameter manually or automatically. It is essential to keep the cutting edge sharp so that the outer insulation can be cut in one stroke.
Crimping end sleeves. The crimping tool has trapezoidal or square shape. They can be with or without flanges. In order for the clamping of contacts to be reliable and accurate, the pliers must be selected according to color coding, which corresponds to a certain diameter.
Crimping pliers for insulated ferrules. The tool has an oval shape, and in the matrix there are nests for the press in the amount of three. They are marked in red, blue and yellow. Sleeves, tips and other types of connectors with a similar color indication correspond to these colors. This marking performs the connection of insulated tips, placing them in the desired socket.
Crimping of uninsulated tips. The main working element is a special rod located along the separation seam and compressing the sleeve in the center.

Crimping with hydraulic tool

High-quality crimping significantly improves the current conductivity at the joints, prevents overheating and emergency situations due to poor contact. At home, for these purposes, ordinary household tongs are used, designed to work with wires with a cross section of up to 4 mm2.

For continuous or combined crimping of a cable with a cross section of 4-400 mm2, it is necessary to use more powerful tools that provide high operating pressure. This category includes hydraulic pliers or hydraulic presses.

The design uses cylinders of various diameters, interconnected and representing a system of communicating vessels. Each of them has a piston. The internal cavity of the cylinders is filled with water, oil or other suitable liquid, therefore such a tool is hydraulic.

In accordance with Pascal's law, the force acting on any point of a fluid at rest is evenly distributed throughout the volume. Thus, if a certain force is applied to a piston of a smaller diameter, then when transferred to a large piston, it will increase. The greater the difference between the areas of the pistons, the stronger will be the force that occurs on the large piston.

Each hydraulic tool of this type has a single, double or triple action. Equipment simple action equipped with one working body - a movable partition. In double or triple action presses, there are respectively two or three working bodies. Their work processes are coordinated with each other, and general management carried out with the help of special distribution equipment.

Structurally, the hydraulic press can be vertical or horizontal, closed or open type. With this tool, you can crimp not only metal, but also other materials.

When choosing a hydraulic tool, the presence of a pressure limiting valve must be taken into account. This element provides additional reliability, eliminating overloads due to pressure. You should pay attention to the types of pressing heads, which are open or closed, as well as the diameters of the working sections. All hydraulic tools consist of sub-groups, each of which performs operations with cables up to 70, 120-300 and 400 mm2.

How to work with crimping pliers

Each pliers are used in accordance with their intended use. However, there are general principles relating to any instrument. When performing each operation, you will need a wire or cable of a certain section, the pliers themselves, as well as sleeve tubes or other connecting elements.

For example, you can take the Internet wires.

The ends of the wires are cleaned of external insulation. This operation will require pliers with a semicircular recess at the bottom and cutting edge above. A wire is placed in the recess, after which its upper side is pressed with a blade. 1-2 turns are made around the cable, the insulation becomes notched and removed without any effort. For normal crimping, you will need a cleaned area, 3-5 cm long.
The cores of cable conductors are aligned and placed in desired sequence by connector type. They are closely pressed against each other and cut so that 1-1.5 cm remains for connection.
The wires are brought into the connecting device with the preservation of the sequence. At the same time, the lower notch of the connector must reach the cable insulation so as not to cause damage when crimping actions are performed.
The whole device is placed in seat ticks. After re-checking correct location flowers are pressed.
Upon completion, the integrity of the connector and the strength of the connection are checked.