RJ45 Connectors: Solid or Stranded?
You’re probably familiar with the ubiquitous RJ45 connectors: It’s the little plug on the end of the cables that connect you to your sweet, sweet internet. Fun fact, their actual name is “8P8C” (for 8 position, 8 connectors), and RJ45 is actually an outdated misnomer based on phone line standards. But since it's virtually universally referred to as RJ45, we'll be sticking with that for the purposes of this article.
“But wait,” you're thinking, “they come in more than one style?” They do indeed, and before you decide on which kind to use, it's a good idea to understand what type of network cable you're going to be terminating.
First off, it's important to note that if you're in the market for RJ45 plugs, then that means you'll be using them with twisted-pair network cable. And whether that cable is rated Cat3, Cat5, Cat5e or Cat6, it's going to be classified as either solid or stranded.
What does "solid" mean?
“Solid” describes cabling whose conductors are made of solid metal, usually copper. Makes sense, right? Because each conductor is made of a single thick copper wire, the cable as a whole is generally more rigid. And since that makes it somewhat resistant to bending, solid cable is most often used in backbone cable runs through walls and conduit, where flexibility isn't really necessary.
What does "stranded" mean?
Then there's stranded cables. These are made up of many fine metal filaments, which are twisted together to form the larger, thicker wire. Because it's composed of 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
So what does all this mean for your RJ45 connectors? Well, once you understand which type of cable you're dealing with, choosing the right plug suddenly becomes a loteasier. 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 mix and match the two, or you'll end up with a bad connection.
It's also very important to note that some RJ45 connectors offer solid AND stranded compatibility. That certainly takes a lot of the guesswork out of it, right? But more often than not, it's going to be one or the other. So why aren't all RJ45's the same?
Well, in order to make a successful connection, a plug's tooth-like contact pins need to properly pierce through the plastic insulation of the accompanying wire. When this is done correctly, the pin is able to physically touch the wire conductor, and ZAP! 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 worthwhile 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".
How do You Identify a Solid or Stranded RJ45 Plug?
So let's say you've got yourself a connector and aren't sure if it's stranded or solid? You may be wondering, is there some way to confirm this visually? Why yes, there is, thanks for hypothetically asking.
We really must stress that the best way to ensure a correct connection is to know which type of RJ45 and cable you're dealing with beforehand. However, if you've got an RJ45 and you're not sure if it's solid or stranded, there are some methods that could help you figure it out. Here's how it's done: if you look at the plug from the side, you'll see the tiny metal connector pins whose job it is to pierce the cable jacket and contact the copper wire. On these pins you'll see little “teeth” that do the poking and then contact the metal in order to make a conductive connection. Typically (and we must emphasize that word) a solid only plug will have longer, staggered teeth, and they will be more widely spaced from each other, since they are only focused on straddling a single, relatively thick wire.
A stranded connector, on the other hand, may have more numerous teeth, and they may be spaced closer together, since their job is to get all up in between the stranded filaments. If the teeth are spaced, the space between is usually shallower. Their job isn't really to straddle the filaments, since piercing the jacket and getting between the strands will make the necessary connection.
And that's really all there is to it. Hopefully now you find yourself a little better equipped to identify your RJ45s, and determine which one you should be using.