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Flat vs Round Ethernet Cables – Everything You Need to Know!

Have you ever wired up ethernet for your home or office? If you’ve ever needed to purchase or install large lengths of the ethernet cable into a home, office, or other building you may have noticed that there are flat Ethernet cables and round Ethernet cables. You might have bought one type because it was cheaper or because it looked nicer, but did you consider the other differences flat and round cables have?  What are the differences anyway?

The difference between flat and round cables is that round cables are easier to install, they’re better protected against EMI, they’re insulated, and also shielded for more durability. Compare them to flat cables that don’t have insulation or shielding but they’re lighter and easily packaged.

Round ethernet and flat ethernet cables have both been around for a while. The two cable types have many other differences, with each type having its own benefits and drawbacks for certain applications.  It could be difficult for you to determine which one to use for your application. How do you know if flat or round ethernet cables are right for you?

Overview of Flat and Round Ethernet Cables

Flat White Ethernet and Round Blue Ethernet Cable

Flat and round ethernet cables perform the same function: they connect wired devices to a local network and the internet.

Depending on your data speed and cable length requirements, you may choose from CAT-5 up to CAT-7 ethernet cables – all of which are available in flat or round designs. Here are some differences and information about flat and round Ethernet cables. 

Flat Ethernet Cables

Flat Ethernet cables, like this one from Jadaol (on Amazon), are made from flat copper wire and have side-by-side twisted pairs. Flat cables are not shielded and therefore can be susceptible to electromagnetic interference (EMI) over longer distances.

They also do not have insulation to attenuate the heat created over the wire. Since they lack insulation and shielding, they’re more inexpensive, lighter, and roll up or package much easier than round cables. 

Another drawback of flat ethernet cables is that they require a lot of maintenance and do not provide high uptime like round cables do.

Flat cables are used mostly in applications where there is low potential for EMI, where you only need to go a short distance, and are better suited for instances where you want to run the cable along a wall or corner. 

Round Ethernet Cables

You could probably guess that round ethernet cables like the CAT7 Shielded Ethernet cable (on Amazon), are round, but do you know what is inside of them?

Besides the round wires, they contain shielding, insulation, and filler that helps keep the round shape. 

Round cables insulate any heat that is generated from the internal wires and they’re protected against small impacts and the elements.

They are commonly used in data centers, in applications requiring long lengths, and in cases where ethernet cables are run through walls.  

Differences Between Flat and Round Ethernet Cables

Flat cables do not have filler and insulation like round cables, so they take up less space and weigh less. The internal electrical wires of flat cables run parallel to each other for the entire length of the cable, for this reason, their electrical quality is better than round cables.

Another benefit of the conductors running in parallel is that they maintain their strength over the cable length. 

Because of all of the insulation and multiple layers of wire in round ethernet cables, they generate a small amount of heat through repetitive motion cycles. This is not a problem with flat cables because of their flat nature. 

Round cables are easy to install and can be fished through walls with greater ease than flat cables. They’re also more durable because the insulation, filler, and shielding are protective. Put simply, round cables require less maintenance and provide better uptime than flat ethernet cables. 

Round ethernet cables are also not as susceptible to attenuation, or the degradation (loss) of data over long cable lengths. Since flat cables are affected more by EMI, over long lengths they could suffer from attenuation.

Round ethernet cables also have more insulation than flat cables. Insulation is a material buffer that isolates conductors (wires) from each other and the outside environment, the insulation is typically a type of PVC. 

Should You Use Flat or Round Ethernet Cables?

Flat White, Round Blue, and Round Yellow Ethernet Cable

Making the choice to use flat or round ethernet cables depends on your application. For most regular home and small network setups, there isn’t a big difference and you should use whatever type you feel comfortable with or already have on hand.

If you are installing in a data center, across long distances, or fishing ethernet cable through an existing wall, round ethernet cables are probably the better choice. 

If you prefer a more cost-effective option; you’re not worried about lower durability, and also prefer better cable management options, you might lean towards flat ethernet cables for your installation.

As always, weigh the pros and cons; know what cable types you have already, and understand what is best for your application before making the decision for flat or round ethernet cables. Making the choice shouldn’t be too difficult after learning about all the differences!

Bending Flat and Round Ethernet Cables

Flat and round ethernet cables can both be bent around obstacles to get your two devices connected and talking. But, did you know that all cable manufacturers specify a bend radius for flat and round cables? The maximum bend radius is the minimum amount you should bend the cable to prevent compromising the internal conductors and damaging it. 

You may have intuitively thought that you should not bend an ethernet cable 90 degrees or more, even if you didn’t know that there are specified bending radiuses.

If you bend an ethernet cable too much you can experience a few things, including a negative impact on network performance, slower data transfer speed, intermittent connection loss, and a loss of data transfer entirely.

For CAT5 ethernet cables, the average specified bend radius is 4 times the diameter of the cable. If the cable diameter is 1 inch (like a typical CAT5), then the minimum bend radius is 4 inches.

Therefore, larger cables require larger bend radiuses. A good rule of thumb is to aim for a bend that is no tighter than the curve of a standard US quarter.

Be careful bending both flat and round ethernet cables, but especially so with flat cables. Because flat cables can be bent more easily due to their design, they are more prone to damage from over bending. Whether you choose a flat or round ethernet cable, be mindful of the bend radius when you install it. 

Ian Gerald

Sunday 20th of February 2022

Flat cables ARE shielded if your a willing to spend the money. These Cat 8 cables will compete with the best of the round cables in most categories.