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How to make your own Ethernet cable

Sure, you can buy Ethernet cables from the store, but where's the fun in that? We'll show you how to make your own.

Ed Rhee
Ed Rhee, a freelance writer based in the San Francisco Bay Area, is an IT veteran turned stay-at-home-dad of two girls. He focuses on Android devices and applications while maintaining a review blog at techdadreview.com.
Ed Rhee
2 min read

Sure, you can buy Ethernet cables from the store, but where's the fun in that? If you want to make custom cable lengths or crossover cables, or repair a broken connector, why not do it yourself? Here's how.

Before you get started, make sure you have the necessary tools, and decide whether you're going to use Cat 5e or Cat 6 network cables.

What you'll need:

  • Unshielded twisted pair (UTP) patch cable
  • Modular connector (8P8C plug, aka RJ45)
  • Crimping tool
  • Cable tester (optional, but recommended)
What you'll need
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There are four pairs of wires in an Ethernet cable, and an Ethernet connector (8P8C) has eight pin slots. Each pin is identified by a number, starting from left to right, with the clip facing away from you.

8P8C connector pins
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The two standards for wiring Ethernet cables are T568A and T568B. T568B is the most common and is what we'll be using for our straight Ethernet cable. The tables below show the proper orientation of the colored wires to the pins.


T568A Standard
Pin 1
White/Green
Pin 2
Green
Pin 3
White/Orange
Pin 4
Blue
Pin 5
White/Blue
Pin 6
Orange
Pin 7
White/Brown
Pin 8
Brown

T568B Standard
Pin 1
White/Orange
Pin 2
Orange
Pin 3
White/Green
Pin 4
Blue
Pin 5
White/Blue
Pin 6
Green
Pin 7
White/Brown
Pin 8
Brown

Step 1: Strip the cable jacket about 1.5 inch down from the end.

Strip the cable jacket
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Step 2: Spread the four pairs of twisted wire apart. For Cat 5e, you can use the pull string to strip the jacket farther down if you need to, then cut the pull string. Cat 6 cables have a spine that will also need to be cut.

4 twisted pair wires
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Step 3: Untwist the wire pairs and neatly align them in the T568B orientation. Be sure not to untwist them any farther down the cable than where the jacket begins; we want to leave as much of the cable twisted as possible.

T586B aligned
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Step 4: Cut the wires as straight as possible, about 0.5 inch above the end of the jacket.

Step 5: Carefully insert the wires all the way into the modular connector, making sure that each wire passes through the appropriate guides inside the connector.

Insert wires
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Step 6: Push the connector inside the crimping tool and squeeze the crimper all the way down.

Crimp connector
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Step 7: Repeat steps 1-6 for the other end of the cable.

Step 8: To make sure you've successfully terminated each end of the cable, use a cable tester to test each pin.

Test cable termination
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When you're all done, the connectors should look like this:

Crimped connector
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That's it. For crossover cables, simply make one end of the cable a T568A and the other end a T568B. Now you can make Ethernet cables of any length, fix broken connectors, or make yourself a crossover cable. Happy crimping!