March 21, 2019

How to Crimp Your Own Ethernet Cables - page 2

First Steps: Snipping and Stripping

  • November 4, 2009
  • By Aaron Weiss

Step 4

When the wires are in sequence, double check against the diagram in case one or two slipped out of position. Using the cutter on your crimper, or a pair of scissors, cut straight across the tips of the wires so they are clean and even.

Grab an RJ-45 plug, with the latch side facing down.

RJ-45 Plug
Guide the wires into the plug, being careful not to let them slip out of sequence. As the cable enters the plug, each wire should slip into its own channel, allowing them to glide smoothly into the plug. Push the cable as far as it will go. You should have about 3/16 inch of cable jacket inside the back of the plug. The wire ends should reach as far as possible toward the front edge of the plug. Wires inserted into RJ-45 plug

Step 5

With the wires pushed into the plug, fit the plug into the crimping slot in the crimping tool. While holding the cable in place with one hand, use your other hand to squeeze the crimping tool with reasonable force. This will press the pins inside the plug into the wires and fasten the plug onto the cable. Crimping RJ-45 Plug

Step 6

Now flip the cable around and assemble the other end. Chances are you want to make a standard, or “straight-through” cable, in which case you should assemble both ends exactly the same.

Alternatively, you could opt to build a crossover cable — a less common cable configuration sometimes used to directly network two devices without a hub or switch in between. To assemble a crossover cable, complete one end following steps 1-5. For the other end, you will change the wiring sequence by swapping the green and orange pairs. This is called a 568A arrangement.

Technically speaking, you can make a straight-through cable using either 568B or 568A, as long as both ends are the same. Mixing arrangements produces a crossover cable. Be sure to clearly label any crossover cables you make, because they will not be compatible with straight-through cables. Though this is less of an issue than it used to be because most modern switches and network interfaces auto-detect the cable type, and auto-configure the connection.

568A Wiring Diagram


Test your cable in a network segment that is known to work. Because small mistakes can cause erratic or non-functional cable operation, it may take a few practices tries to get it right. The most common problem is lack of contact between the pins in the RJ-45 plug and the wires, particularly if the wires have not been pushed in far enough. If your connection is poor, simply snip off the RJ-45 plug and try the assembly procedure again.

If you want to get fancier and arguably more reliable cables, you can also add strain relief boots to your supplies, as well as a handheld cable tester.

Article courtesy of Practically Networked

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