How to Wire Up Standard RJ45 Ethernet Plugs (Cat5e / Cat6 Crimping Tutorial)
How to make up CAT5e or CAT6 ethernet cables from scratch and terminate using RJ45 plugs.
For times when an off-the-shelf patch lead isn’t long enough, knowing how to terminate network cables with an RJ45 plug is a useful skill to have.
To start making your own ethernet cables you will need…
The above links are affiliated which means we may earn a small commission, at no extra cost to you.
So, take your wire cutters and cut however much cable you need for the cable run you’re working on — being sure to leave a generous amount of excess, partly because a few centimetres will get chopped from either end, because it’s always better to have a little bit of excess rather than realise the cable’s too short! Some crimping tools also include a cutter and a stripper, although I tend to use my own separate wire cutters and strippers — but it’s up to you.
If you’re going to be putting strain relief boots on, slide one on now before you proceed to start putting the end on.
Network cable consists of 4 twisted pairs, so 8 wires in total. Cat6 cable usually also has a loose plastic core running down the centre, to reduce crosstalk between those 4 twisted pairs. Each pair is colour-coded, with one of the pair being a solid colour and the other is a tribute act to an American rock duo from Detroit.
Strip off about a 3cm length of the outer jacket, being careful not to damage the conductors inside. Snip off the plastic crosstalk separator and the ripcord thread that both run along inside the cable. Then untwist all 4 pairs of wires, and pinch each wire tightly between your thumb and forefinger and run along like this to straighten them all out as best you can.
You can use the bit of jacket that you’ve just stripped off to help untwist the pairs if you like, by sliding it down between them like this. Many people prefer doing it this way, as it’s a bit easier on your fingers!
Next, it’s time to arrange the 8 wires in the correct order so that we can feed them into the plug. I keep this little printout in my tub of connectors, or you can just Google “RJ45 wiring diagram”. There are 2 main standards, T-568A and T-568B — the only difference is the greens and the oranges trade places. The key importance is that the wiring is the same on both ends of the cable, so if you’re just making a length of cable for yourself at home and terminating both ends with an RJ45 plug then it really doesn’t make any difference — as long as you use the same both end. I tend to use T-568B because it’s the most widely used.
So that’s orange and white, solid orange, green and white, solid blue, blue and white, solid green, brown and white, solid brown.
If you’re adding cabling to an existing setup, or replacing a faulty end, then make sure you use whatever standard is already in use at the location, to make things easier for yourself and any other engineers who might do work there after you.
So, arrange them in the right order and again, run your fingers along to help straighten them out even more so that they sit right and in the correct position. I find it helpful at this point to take my wire cutters and gently grip the cables — but don’t snip them just yet — and to bunch the ends right up to each other and double check the colours are still in the correct order.
Then, take an RJ45 plug and hold it up against the end of your cable, and line the end of the outer jacket up with the point that it’ll end up at inside the plug. The key here is that we want all 8 wires inside the plug to be long enough to reach right to the very end, but not so long that the outer jacket isn’t gripped securely when we crimp it in a moment.
Then slide your snips down the wires, keeping them bunched together and in the right order, and come to rest in line with the very tip of the RJ45 plug. Put the plug down for a moment and hold the wires really tightly between your thumb and forefinger as you snip the excess off, so they stay bunched together and in the right order.
Then, being careful not to let them come loose, slide them up and into the plug with the clip end facing away from you. Make sure you push it all the way to the pins at the end and so that the outer jacket is fully inside ready to be gripped when you crimp.
Visually inspect the colours to make sure they’re still in the right order, and then use the crimping tool to finish the job. This does two things: it splices all 8 wires into the copper pins at the end there and it bends the gripper to hold the entire cable securely inside the plug.
You can then slide the strain relief boot up and over the clip and that’s the first end done! Repeat exactly the same process with the same wiring order for the other end, and then be sure to test the cable with a cable tester like this.
This checks all 8 wires individually — it will tell you that the 8 connections are good on both ends and also that it’s wired up correctly on both ends in the right order — or at least the same order both ends. It does this by sending a pulse down each wire in turn, from the Master to the Remote. You should see the sequence going from 1 to 8 on both ends, and when it does you know that the cable is working perfectly. If it’s a long cable run — and both Cat5e and Cat6 cable are good for 100m — then you can separate the Master and Remote parts of the cable tester and put one at each end of the cable run to test it.
Sometimes, rather than an RJ45 plug you’ll want to terminate the network cable to a keystone jack in a wall socket.
Purchasing Links: (paid)
➡ RJ45 Ethernet Crimping Tool: https://geni.us/RJ45Crimper
➡ Ethernet Cable Tester: https://geni.us/NetworkCableTester
➡ RJ45 Plugs: https://geni.us/RJ45Plugs
➡ Punch Down Tool: https://geni.us/PunchdownTool
➡ Cat6 Ethernet Cable: https://geni.us/Cat6
➡ Wire Cutters / Snips: https://geni.us/Snips
DISCLOSURE: As an Amazon Associate we earn from qualifying purchases.
Originally published at https://www.switchedonnetwork.com on November 29, 2021.
