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Crimping Ethernet Cables


As part of our office re-arrangement, we needed to consider our new networking layout to minimise un-tidy cables runs. We needed custom made lengths of Ethernet cables to connect all the different computers and devices in the office.

Crimping is the process of attaching the RJ45 connectors to the stripped wiring so it snugly fits. This post shows you how to easily create your own cables.

Some pre-requisites

Firstly, you need to consider if you are creating a standard Ethernet cable (called straight through or patch) which connects your PC to a networking device like a switch/router/hub. There is another type of cable you can make called a crossover cable for when you want to connect devices of the same type (eg. PC to PC/switch to switch). The only difference is the colour order you wire it in. NOTE: Regarding crossover cables, nowadays connecting switch to switch, switch to router don't rely on using a crossover cable. The devices are able to work with either cable. PC to PC still needs crossover though for an ad-hoc network.

You may want to buy specific Ethernet cable depending on what speed you want and how far you need to go. This is fine as long you aren't making over 100 meter lengths. Normal 100Mbps (10 megabytes per second) cable is CAT5. The faster 1Gbps (100 megabytes per second) cable is CAT5e or CAT6 for speeds (CAT6 is preferred).

What do you need?

Ethernet cable (buy it in roles if you need a lot), a crimper, 2 RJ45 connectors per cable (buy these in bulk packets), and some patience. A standard crimper like the one at comes with the cutting blades needed to cut and strip the cable and the RJ45 connector to secure your connector to the cable (crimp it)


1. Cut off a decent sized role of cable from your reel. Lay it out along the ground and cut it with your crimping device. You want enough room so you can redo the crimping if you make a mistake and you don't want any strain on the wiring and connectors

2. Use the crimper to strip off about an inch of the outer shielding to expose the 8 wires inside the cable

3. The cables will be twisted together (twisted copper pair is the name given). Start with the white/orange cable on the left and put them in order. Try your best to avoid crossing over cables so they look tidier) Below is the order they should be in: (Ref

4. Once you have them in order give the cable a little flex on the rubber shielding

5. Next they may need to be cut flush. Not always necessary but it makes the cables go into the connector easier. Just trim off a few millimetres off the end if you feel the connectors aren't nice and flush

6. Once you're here you just need to put your connector on the end. You want maybe half an inch of the rubber on the cable at the bottom not just the 8 wires barely holding on. Gently put in the wires to the connector with the gold pads (NOT THE END WITH THE LOCKING ARM) and push it into the connector

7. Now put the head into the hole on the crimper and give it a couple of tight squeezes so it will stay on permanently

8. Repeat from step 2 for the other end of the cable

This should be it. We have a short video showing these steps in detail below.

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