Crimping pliers - what is it, their varieties and applications

The key to any high-quality electrical connection is the contact area of ​​the wires - the larger it is, the more reliable the contact. Of course, all this is selected with respect to the cross-section of the wires to be connected, so the main thing here is to do without fanaticism. If the first connections of this type were long twists crimped with pliers, now these are straight wires that the crimping pliers fasten together 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 tips, but this is fully compensated 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 ways of using - preparing live conductors to fix them in the terminals of sockets, switches and other electrical appliances, as well as connecting several wires to each other.

In the first case, crimping is justified if stranded wires are used. If you squeeze them into the terminals of the contacts without preparation, then over time, under the influence of an electric current (it creates microvibration), the veins will "shake", there will be free space between them and the contact will generally weaken.

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

Also, crimping is used when working with cables of large cross-section - it was used even long before the appearance 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 pocket-sized. To create the necessary force, such devices use the principle of a jack or a separate hydraulic drive - human forces, even applied through a conventional lever, are not enough to properly crimp a thick cable. 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 gathered together, a sleeve is put on them and crimped. In this case, the wires can be inserted into the sleeve from one or both sides: in the first case, a semblance of twisting is obtained, and in the second, a sleeve.

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

Varieties of crimping pliers

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

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

In the video, various types of wire crimping tools:

The advantage of such devices that crimp wire cores is in their relative versatility - they can be "approached" from either side with the tips.The main disadvantage lies in the need to have several such ticks "in the grip", since cuts for 3-4 sizes of liners are usually placed on the sponges. Alternatively, you can purchase a universal crimper for crimping with replaceable dies that are attached to a special cassette. If it is necessary to work with other types of handpieces, the old ones snap into 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 their complete wrap-around, they perform better and tighter crimping of the end of the cable, 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 press a sleeve into which the wires are inserted on one side - otherwise the tongs will remain on the wire, since their head is closed.

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

How to work with crimping pliers - important nuances

The very process of crimping the wires is intuitive - the sleeve or tip is put on the wire (s), a matrix of pliers is brought to it, the tool handles close and the contact is ready. In practice, however, most often the "first pancake", or even a few, are "lumpy", and practically in the literal sense - connections can be far from ideal. There were also cases when, in view of a well-crimped wire, contact worsened over time.

If the shape of the terminals is not maintained

In the first case, the settings of the squeezing force of the matrix parts are to blame, which can be different for both individual wires and the terminals themselves. Because of this, pros prefer to have at least two tools so that they don't have to readjust the spring to work with other wires or sleeves.

The quality of work is also affected by the material from which the sleeves are made and their thickness. Crimping for tight terminals is always much easier and they subsequently hold their shape better than those made from soft materials.

The correct orientation of the tips with the "U" -shaped section is, although lying on the surface, but often ignored requirement, and in fact the skew 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 ferrules is performed, then it must be got rid of. The validity of this statement can be verified by simple experience - take a pair of single-core single-wire wires, arrange them crosswise and squeeze them with pliers. In some cases, both wires are deformed, and sometimes only one, but at the same time it will be almost completely interrupted and will begin to dangle on a thin isthmus. Of course, the conductivity of this vein will decrease significantly.

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

Nuances of casing wires in the video:

Color marking of sleeves and dies

Some manufacturers mark different sleeve sizes with separate colors and apply the same marks to the jaw matrices.

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

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 generally needed for each type of wires used, if there is no desire to fiddle with adjusting the spring force. Therefore, what specific tool is needed and in what quantity can be decided only on the basis of everyday work tasks.