Crimping Twisted Pair 8 And 4 Cores: Crimping Schemes + Step-By-Step Instructions

Computer networks are a traditional reality of modern digital technology. Such structural elements are used everywhere and on a large scale. In the meantime the network constructions make a mass use of a special cable, by means of which the individual points (nodes) are interconnected.

This cable is technologically seen as the standard execution of products of this type, and the peculiar feature of the product is the twisted pair - two conductors. These conductors are twisted one to the other along their entire length, being insulated. A certain twisting pitch is observed.

We will tell you how a twisted pair is crimped to make a reliable contact. In our article we will describe the connection of a four-core (2-pair) and an eight-core (4-pair) cable. With our tips you will do the whole front without any problem by yourself.

Content of the article:

  • Peculiarities of crimping an 8 and 4 wire
    • Schemes for crimping mains cable lugs
    • Direct and cross configuration
    • Purpose of this or that scheme
  • Step by step instructions for crimping mains cable
    • Step #1 - cable preparation
    • Step #2 - cutting insulation
    • Step #3 - preparing the wires for loading the plug
    • Step #4 - crimping pads
    • Step #5 - quality test of the press
  • Applying unusual pressing techniques
  • Conclusions and useful video on the subject

Pecific features of crimping an 8 and 4 core

Before we explain the crimping technology of copper wire make up the internal contents of a network cable it is logical to become familiar with the lug wiring variations.

Mainsplug crimp diagrams

The termination is a plastic plug of the standard 8P8C series connector. Such a connector (plug + receptacle) is often classified by \"connoisseurs\" of computer networks as an RJ45 connector.

But this classification is incorrect. But it is just for general information.

Crimping twisted pair 8 and 4 cores: crimping schemes + step-by-step instructions

The appearance of the lugs (eights) of a network cable whose contacts are subjected to a crimping procedure when first used. Once crimped, the lugs are not used for reuse

As shown by the series designation (8P8C), the plastic plug and socket are also 8-pin. These eight pins can be connected in different arrangements, depending on the type of cable connection.

In fact, there are two standards for the wiring of the T568A and T568B plug and two ways to crimp them:

  1. Direct.
  2. Cross.

For easy untying of a twisted pair cable and subsequent crimping, each wire is marked with a specific color. Moreover, the cores of the same pair are similar in color. For example, the classical coloring of the first pair for the T568A standard for direct crimping of the first twisted pair: 1 - green-white; 2 - green.

Crimping twisted pair 8 and 4 cores: crimping schemes + step-by-step instructions

The coloring standard of the cores of an eight-core network cable: upper picture - standard T568A; lower picture - standard T568B. As you can see from the pictures, the difference in the standards is noted by the color designation of some paired cores. 1 and 8 are core numbers

Direct and crossed configuration

What the difference between direct and crossed wire crimping schemes for copper conductors should be obvious. The straight configuration provides a circuit solution when the core numbers (coloring) on the two opposite ends of the network cable are identical.

The crossed configuration respectively provides a circuit solution when the conductor numbers (coloring) on the opposite ends of the network cable are marked in a slightly different way to each other. In particular, conductors 1,2,3 and 6 are swapped.

Crimping twisted pair 8 and 4 cores: crimping schemes + step-by-step instructions

Cross-circuit configuration for 100 Mbps applications: 1 - white-orange / white-green; 2 - orange / green; 3 - white-green / white-orange; 4 - green / orange

The two crimping arrangements provide the conductor arrangement on the opposite end-plugs considering the numbering convention, where the first wire is placed opposite the 8th and conversely the 8th wire is placedĀ opposite the first.

In addition to these two schemes, there is another one called \"cantilever\". In this case the conductors on the end-plugs are arranged in inverted order.

In other words, the first conductor of one plug corresponds to the first conductor of the other plug and consequently the eighth wire at one end corresponds to the eighth wire at the opposite end.

Crimping twisted pair 8 and 4 cores: crimping schemes + step-by-step instructions

Continental crimping scheme for copper wire in a power cable. It is characterized by the fact that the end-plugs are placed relative to one another in an inverted position, where wire 1 = 1; wire 8 = 8

Purpose of one or another scheme

The concrete application of the described twisted pair crimping schemes is determined by the connection variations of computer equipment. As a rule, the direct configuration is used for the connection of a network card and a switch (hub).

Cross configuration is usually used when there is a need to connect two network cards of personal computers. The same scheme was used for the communications of obsolete models of communicators (hubs).

We should note an important detail: at the current stage of development of digital technology, the cross configuration has practically lost its importance. This is due to the development and implementation of technology for the automatic detection of the signal circuits of network terminals.

Crimping twisted pair 8 and 4 cores: crimping schemes + step-by-step instructions

The \"console\" crimped cable configuration is traditionally used for service purposes. For instance, the configuration of a communicator (router) via a PC is made via this circuit

Step-by-step instructions for crimping a network cable

Considering that cable connections are used quite often in a variety of environments, including households, the question how to crimp an 8 core cable is quite relevant. Especially if it is not the experts but the usual users - the PC owners who are concerned.

Let us look at this simple technological process in order to make it easier for the potential creators of home network circuits.

When working on twisted pair cable a special tool is required:

  • crimper;
  • ripper;
  • a common knife.

The first two tools with exotic names are the special press designed to resemble in execution the usual electrician's pliers and the cable strip cutter.

The cutter is in fact an ordinary knife, the only difference being that it is additionally equipped with notches for removing the insulation coating.

Step #1 - cable preparation

Where the number of cores and the right length are required. For home use it is often necessary to crimp a 4-core twisted pair copper pair, i.e. a piece of four-wire cable is required.

In principle, the use of an eight-core cable version is not excluded either. In this case the unused pairs are simply not used. Another issue is economy, because the price of four-pair products is higher than two-pair.

Crimping twisted pair 8 and 4 cores: crimping schemes + step-by-step instructions

Fragment of network cable where eight copper conductors are placed under the jacket - four twisted pairs. This option is often suitable for domestic connection problems

Step #2 - Cutting the Insulation

After preparing a piece of the desired length, the insulation on the short end sections of the network cable must be carefully removed. It is sufficient to step back from the edge of the end cut 40-50mm and then cut the cable jacket with a light circular pass.

Crimping twisted pair 8 and 4 cores: crimping schemes + step-by-step instructions

Cut the cable jacket with a specially designed cutter for this purpose. As you can see from the picture the tool is equipped with different shaped notches giving a better cut

It is recommended that this operation is carefully carried out so as not to damage the insulation of the inner conductors. Usually the sheath is not cut to its full depth, but only partially. Then the cable is gently bent in the area of the cut, so that the sheath is torn in a circle.

The cable sheath can be removed easily and efficiently by using a cable stripper. However, you will have to spend some time mastering this tool beforehand. Even professionals are rarely able to pull off a good stripper in one go.

Step #3 - Preparing the strands for loading the plug

The exposed, twisted pair conductors in the area freed from the cable sheath should be untwisted and smoothed out. Copper conductors in thin insulation are soft enough, so it is easy to do this.

Then all wires should be aligned relative to each other and cut off exactly perpendicularly, leaving 2-3 mm from the end. This is easy to do with a pair of paper scissors. The result should be an even end row of four (or eight) insulated copper strands.

Crimping twisted pair 8 and 4 cores: crimping schemes + step-by-step instructions

The built up conductor row should always be trimmed before loading in the body of the plastic plug to obtain an even end line of the entire row. The trimming is conveniently done with an ordinary pair of scissors

A new plastic eight-pin (8P) plug will be used next, on which the crimping - the contact attachment of the copper strands will be performed. Please note that 4-pin plugs for computer networks do not exist. Therefore an 8-pin plug is used in every case.

Step #4 - Crimp pads

The back of the plug (8P) is technically the entry gateway for the copper wire loading. A kind of lock contains eight rectangular cells, where the colored wires are loaded.

The copper cores of the network cable are loaded in the \"lock\" of the contact plug without removing the insulation. The wires are simply inserted into the channels as far as they will go.

Then a standard 8P8C jack press is used. The press pad is placed on the plastic plug and then the handles are squeezed until a characteristic click is felt.

Crimping twisted pair 8 and 4 cores: crimping schemes + step-by-step instructions

The contacts of the plastic end-plug are crimped by means of a crimping tool. It is recommended to press the cable towards the plug with the free hand until the process is completed

Step #5 - testing the quality of the press

After crimping the press is removed, the joint is tested for strength by attempting to physically pull the conductors out of the plug. If everything is done accurately, the strength of the crimp will not allow the strands to be removed from the pressed slots.

This concludes the crimping procedure. The same process is carried out on the opposite end of the cable.

The termination of the crimping of the two cable ends is usually followed by a subsequent electrical test. A special tester including a transmitter and a receiver for the test signal is used for this purpose. The treated cable is inserted into the device and the control LEDs test for continuity of connections.

Crimping twisted pair 8 and 4 cores: crimping schemes + step-by-step instructions

A specialized test device for the electrical connection quality of crimped conductors. Usually used at the professional level. In the household it is possible to apply a simple cable-crimping technique

Use non-standard crimping techniques

Conscious that purchasing a special tool (the same crimper) requires money, some craftsmen use a non-standard method of crimping wires. An ordinary electrician's screwdriver with a flat blade of a suitable width and thickness is used.

This method compresses the contact pins, one by one, inside the body of the plug.

Crimping twisted pair 8 and 4 cores: crimping schemes + step-by-step instructions

The screwdriver method is \"barbaric\", but works. True, the pressing is not always of good quality and as a result the network cable becomes unstable

If the twisted pair has to be extended, the works are carried out according to the procedure detailed in the following article. We recommend reading this useful informative material.

Conclusions and useful video on the subject

The video below demonstrates the domestic version of cable crimping, the special tool used and the step by step process.

This video, although not entirely technically correct, helps to understand the process more completely.

The procedure of crimping copper cores of network cable can be learned in theory without much difficulty. However, even with theoretical knowledge, a practical skill is definitely required.

In fact this skill is built up rather quickly, even when faced with the job for the first time. It is true that a beginner cannot do without spoiling a couple or three plastic forks - he will have to practice first. This is the law of practice.

Please leave comments, post pictures, and ask questions in the box below. Tell us about how you crimped the twisted pair with your own hands. Perhaps you know techniques and methods that will be useful to visitors.

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