We know what you're thinking: RJ45 connectors come in more than one style? They do, and before you decide on which kind to use, it's a good idea to understand what type of network cable you'll be terminating with them. If you're shopping for RJ45 plugs, then that means you'll be using them with twisted-pair network cable. And whether that cable is rated as Cat3, Cat5, Cat5e or Cat6, it's going to fall under the classification of either "solid" or "stranded."
What does "solid" mean?
“Solid” describes cable whose conductors are made of solid metal, usually copper. Because each conductor is made of a single thick copper wire, the cable as a whole is generally more rigid. Because it's somewhat resistant to bending, solid cable is most often used in backbone cable runs through walls and conduit, where flexibility isn't really needed.
What does "stranded" mean?
On the other hand, the conductors found in stranded cable are made up of many fine metal filaments, which are twisted together to form a larger, thicker wire. Because it's based on thin wires, stranded cable is a lot more flexible than solid, so it's commonly used in patch cords and other shorter network cables that need to be able to flex and bend during use.
Choosing the Right RJ45 Connector
Once you understand which type of cable you're dealing with, choosing the right RJ45 plug suddenly becomes a lot easier. It's basically just a matter of matching cable type to connector type: solid goes with solid, and stranded goes with stranded. Just be sure not to combine the two, or you'll end up with a bad connection.
Why aren’t solid and stranded components cross-compatible?
In order to make a successful connection, a plug's tooth-like contacts need to properly pierce through the plastic insulation on each wire. When this is done correctly, the plug contact is able to physically touch the wire conductor, and a connection is made. It's a simple concept to understand, but because of the differences between solid and stranded wire, the insulation-piercing process is a little different for each type.
While solid RJ45 teeth only need to make contact with one wire, stranded RJ45 teeth need to work their way in among multiple strands in order to make a connection. The subtle differences between connector contacts can be tough for the untrained eye to identify, but can cause some pretty big problems when paired with the wrong type of cable. Save yourself time, frustration and wasted supplies by verifying that your cable and RJ45 connectors "match".