How to Terminate a Cat 5 Cable





Introduction: How to Terminate a Cat 5 Cable

About: I'm a college student who doesn't have enough time to make the stuff he'd like to make. I like to make jewelry, but don't have any jewelry Instructables. I plan to change this.

Alright, the average person may not ever need to terminate (crimp a connector onto) the end of a Category (Cat) 5 cable, but perhaps you will someday. Just in case you do, I hope to create a foolproof guide containing all the information you need to do so. But enough of the intro, you came here for some info, so let's terminate some cables!

The Cat 5 standard has been updated to the Cat 5e standard. However, the crimping configuration remains the same, so these instructions will work for either standard.

There are some excellent additional tips and elaborations on procedure in the comments, so I'd recommend that you read those too as you go through these steps. 

Step 1: Materials

In order to successfully terminate your Cat 5 cable, you will need:

~ Cat 5 cable
~ 8P8C (8 pin 8 contact) connectors - (these are also referred to as "RJ45" connectors)
~ A modular connector crimping tool
~ Wire cutters/strippers (may not be needed depending on crimping tool)

Step 2: Prepare Wire

First, strip off one half inch of the outer jacket on the cable. Do not cut the colored strands of wire, and note that this is the material holding all eight strands of wire together, not the coating on the individual strands. It is important to not strip off the colored coatings on the small wires, as these will be used for identification later. It is also important to strip close to one half inch off. If more jacket is stripped, the connector will not properly grip the cable, and the crimp may fail. If less jacket is removed, the strands may not fully insert into the connector. Depending on what kind of crimping tool you have, it may have a feature built in to do this for you. However, I prefer to do it myself because the crimping tool usually cuts half way through some of the strands. 

As mentioned by cwolsey in the comments, you may want to strip off more than 1/2 inch, arrange the wires (which you will learn to do in the next step), and then cut them down to length to make sure they're straight on the end. 

Step 3: Put the Strands in Order

There are two orders the colored strands can be put into before inserting them into the connector. Both standards: T568A (A) and T568B (B) work equally well. One cable using the A standard can also be connected to another using the B standard and the system will work fine, but it is important that both ends of the same cable are terminated using the same standard.* The color order for each specification is illustrated in the second picture. Get the wires into the correct order for whichever standard you are using, and flatten them out in order. If you have difficulty getting the wires in the right order, keep trying. It can be done.

*Unless one is trying to create a crossover cable. You can read about them here:

Step 4: Insert Cable Into Connector

Perhaps the hardest part of terminating a Cat 5 cable is inserting the cable into the connector while keeping the strands in the right order. Once the strands are in order, insert them into the connector. Once they're in, check to make sure they're in the correct order by color. Then, push the cable into the connector so the strands go all the way to the front.

Step 5: Crimp

Insert the connector into the crimping tool and use your big muscles to squeeze the handles until it's crimped. (As mentioned by Servelan in the comments, you should push the cable into the connector as you crimp to make sure it doesn't come out.) If your tool ratchets, you'll know it's done when the ratchet releases. If not, just squeeze nice and hard to make sure you get it tight. Congrats, you just terminated a Cat 5 cable! If you need to terminate both ends (as you likely will), repeat the steps in this Instructable, making sure you use the same order of wires (specification) that you used for the first end. Now you no longer need to bow down to the man and buy expensive 5 foot patch cables. You can get some cable cut at the store and make your own, as long as you need, and much cheaper too.

Step 6: Keep Those Tabs From Breaking Off

8P8C connectors are great, but they have a problem. The little tabs that hold the male connector (the one you just crimped onto a cable) in the female connector (what you will plug your cable into) always break off. When this happens, the cable just falls out of the receptacle, and that's no fun. To keep the tabs from breaking off, you can buy little things called boots to put on the cable, but they're expensive. Instead, just wrap some tape around the back portion of the connector and tab. Make sure you don't tape any part of the connector that has to go into the receptacle. You might want to use some more durable tape (such as electrical or quack quack) than the plastic stuff of a certain brand that I used. It's starting to rip.



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    I found I stripped about 3/4" of the jacket of, straightened the wires, cut them down and shoved the jacket back up as I put them in and had no issues. Make sure you have a few extra connectors and a bit of extra cable. I messed up twice before getting the hang of this.

    Good tutorial,

    I would say that I would strip a lot more off the jacket (2"). Then trim the wires to the correct length with wire snips or scissors after you have straightened them out and put them in the right order. that way it is a lot less fiddly and you get all the cables exactly the same length. Sometimes if you have a cables slightly shorter than the others it slightly misses the pin as it is crimped. Like the Green and brown wires in the photo above.

    That is the way I have been taught anyway :-)

    2 replies

    That sounds like a good idea. It would probably be easier to put them in order that way too.

    Once the cable jacket (or sheath) has been cut and removed, and the wires are exposed as four pairs, pinch the open end of the cable jacket tightly where the four pairs of wires emerge, and remove the twist in each pair by pulling each individual wire into a straight(-ish) section--repeatedly drawing a thumb and forefinger over the exposed length, allowing the thermoplastic cover of each wire to slide through your finger tips.

    Once all eight are done, and while still pinching the end of the cable jacket, order all the wires as they're intended to lay once the connector is crimped. As cwosley has said in a prior comment, once all the eight wires are laid out in the proper order is the time to cut them to length, which you'd do with the blade-and-anvil of the crimping tool.

    At this point, as you visually scan across the row of wires you've prepared and have pinched between your thumb and finger, they should alternate between solid-coloured and striped (this is a general description, applicable to either scheme used, A or B). In other words, you shouldn't see two solid-coloured wires adjacent to each other, nor two striped wires. A more through-going sanity check is to ensure that you've arranged the wires in the proper order as described in this instructable.

    Immediately after the above checks, insert all eight wires simultaneously into the connector, and with some force. At this point, you can take out some insurance against a missed wire by looking at the connector end-on: you should see eight bright copper wire ends, all lined up, and all at about the same depth behind the (typically) transparent material of the connector itself. Once you've verified that all eight wires are fully inserted (all come to end 'just behind the glass'), and that the cable jacket (or sheath) protrudes into the connector beyond the crimp wedge, complete the job with the crimping tool.

    One way to do this (and as mentioned, you should do more than 1/2") is to take some scissors with fine points and carefully cut along the length of the insulation for the desired distance and then carefully cut around the circumferance of the length of the insulation you want to remove.

    If you're planning on making several of these, it helps to have a cable ring tool, which basically works like a small razor blade to cut the insulation around the cable. They're cheap and well worth the cost to eliminate the frustration of having cut one of the actual wires' insulation.

    3 replies

    My wire strippers have a sort of round cutting area, so I use them to cut most of the way through the outer insulation, and then bend it back and fourth slightly to get the rest of the way through. What does that tool look like? I'm not quite sure which Google Images result to believe.

    Home Depot carries a cheap one like this: IIRC, it was under $4. Here's another style:

    They're also known as cable strippers, but that could include coax, so when my then boss objected to my nickname for the thing (not knowing its name, I called it a 'twirly bob', sort of a thingamabob you twirl) I took pains to find out the formal name. : )

    i cheat when i do this......
    i cut 1-1.5 inches of the jacket off then insert the wires one by one... then shove a packet of surgu around it to protect the wire

    I managed to find a set of "all in one" crimpers that include the jacket stripper into the design. all you have to do is rotate the crimpers 360* and the jacket falls right off.

    When choosing a brand of RJ-45 Connectors, i personally use Belkin. they actually have a section in them that gradually gets to the size of the inner wires, and help to keep the inner wires the way you put them before inserting them into the connector. all in all tho, good instructable!

    One little trick: push the wire into the connector as you do this to make sure that the wires didn't slide out, and then crimp while pushing.

    Back before wireless, I had the cable modem in the office, and the wife's computer in the family room. I had to run 50 feet of cables through the basement to get her Internet. It was so much easier than I thought it would be!

    People, it really is this simple. This is a good step by step guide on how to crimp a cable. The rest of the process is just as easy.