TUTORIAL

Make Your Own Custom Cables

by Leslie Rutberg

Making your own Ethernet cables is an essential skill for any IT professional or tech enthusiast. Whether you’re setting up a home office or preparing for hands-on IT tasks, understanding how to cut, strip, and crimp cables can save you time and money. In this tutorial, we will guide you through creating your own RJ45 cables, using the T568A or T568B wiring standards.

Project Overview

EXPERIENCE LEVEL: Entry-level

TIME TO COMPLETE: 1-2 hours

ESTIMATED COST: $50–$150 (depending on the tools you purchase)

Tools and Materials Needed

This kit is a great starter kit for those who need all their basic networking tools in one go. Or you can choose individual tools from the following options.

• Crimper tool 

• Punch down tool 

• Stripper/butter

• RJ45 Cable heads 

• Ethernet cable 

• Network tester 

• Tone generator (optional, but useful)

Skills Needed

• Basic understanding of networking

• Familiarity with physical networking equipment

Before You Begin

Before you start, make sure you have a general knowledge of networking and are familiar with the T568A and T568B wiring standards. You don't need a specific certification, but it's helpful to have an IT background and a DIY mindset! Make sure you have a quality crimper and tester to make sure your cables are functional.

Making your own Ethernet cables is cheaper than purchasing pre-made cables, especially when working with custom lengths or in bulk. It also means you can tailor the cables to your exact needs. 

More importantly, mastering this foundational skill gives you a deeper understanding of how network connections function, which can help you quickly diagnose and resolve connectivity issues—an essential skill for any IT professional. Even better, this is a really simple skill to learn. 

Step 1:  Cut the Cable to Length

Measure the length of the cable you need. Make sure to add a few extra inches to have enough wire to work with. Cut the cable using the cable cutter feature on your crimper tool.

Step 2: Strip the Cable 

Use a cable stripper to remove the outer plastic shielding. You only need to strip a small amount—just enough to expose the bundled twisted pairs inside.

Step 3: Untwist the Pairs 

Once the outer layer is stripped, untwist the pairs of wires down to the insulations. These wires will be color-coded (green stripe, green, orange stripe, orange, blue stripe, blue, brown stripe, brown.)

Step 4: Cut the Insulation 

After untwisting the wires, carefully cut out any excess insulation, using your wire cutter. Slide the cutter along a short length of the cable, which will rip the insulation off. Make sure the length of stripped wire fits into the RJ45 cable head. 

Step 5: Arrange the Wires in the Correct Order 

Refer to the T568A or T568B wiring standard (whichever you’re using) to arrange the wires in the correct order. Flatten them to ensure they are properly aligned before trimming them to the appropriate length.

Step 6 Insert the Wires into RJ45 Head

Gently push the wires into the RJ45 cable head, ensuring they stay in the correct order. Make sure the wires extend far enough into the head so they make proper contact.

Step 7: Crimp the Cable 

Use the crimper tool to firmly crimp the cable head onto the wires. Make sure to use the slot on your crimper that matches your wire's gauge.The tool will also cut off any excess wire sticking out of the head.

Step 8: Test the Cable 

Once the cable is made, it’s time to test it using a network tester. Option A testers will check if the order of the wires is correct, while Option B testers offer more features, such as checking for continuity, shorts, and crossed wires.

Troubleshooting Tips for Making Custom Cables

When making your own cables, it's easy to run into a few common mistakes. Luckily, they're usually pretty easy to fix! 

1. Incorrect Wire Order: A frequent issue is arranging the wires in the wrong sequence, especially when following the T568A or T568B standards. Double-check the color-coded order before inserting the wires into the RJ45 head to avoid miswiring.

2. Improper Crimping: If the wires aren’t properly crimped, the connection will be weak or non-functional. Ensure the wires extend far enough into the connector and crimp the cable firmly, using the appropriate slot for the wire gauge.

3. Cable Shielding Damage: When stripping the cable, it's easy to cut too deep and accidentally nick the internal wires, which can cause intermittent connectivity issues or  complete failure. Be careful when using the stripper tool. Practice applying just enough pressure to remove the outer shielding without damaging the internal wires.

4. Failed Continuity Test: If your network tester shows the cable has open circuits or crossed wires, it’s likely due to a poor connection or incorrect wire placement. Re-check the wire alignment and test for loose or misaligned connections. You may need to cut and re-crimp the cable to fix it. 

Conclusion

Just like that, you've made your own custom-length cable! You can use this method to make patch cables or to make custom-length cables that are built into the walls, even in your own home.

To learn more about cabling, networking, and all the practical skills you need to be a real IT pro, check out Jeremy Cioara's course, IT Expertise: Installing Network Cabling and Devices or any of our other tutorial pages.