What is a Keystone Jack? vs. Coupler (RJ11 RJ12 Cat5e, Cat6, Cat6A, or Cat8)

In this article, we explain what is a keystone jack. This post explains the ins and outs of these jacks used in various electronic equipment.

Keystone jacks are important components in expansive LANs that utilize wall plates and patch panels. Essentially, they are female connectors for connecting various kinds of the broader network, designed to insert into patch panels, surface mount boxes, and modular wall plates.

Also Read: What is USB4? Is it Better than Thunderbolt or USB-C?

A keystone plug is the matching male connector, typically connected to the end of a cord or cable.

The name ‘keystone’ is derived from their appearance, identical to architectural keystones. Also, it is known that the term ‘keystone’ is derived from the distinctive shape of the jack, which resembles the standard RJ-11 wall jack being used to connect fax machines, telephone sets, and dial-up computer modems to traditional telephone lines.

They enhance the versatility of patch panels by providing administrators with fine control over the kinds of connections used in the modular patch panels for more diverse network connections.

In other words, a keystone jack is a systematized plug-in package helpful in mounting low voltage electricals. Commonly, it is referred to as a module that is being used to connect to different keystone wall plates, patch panels, and surface mount boxes. You can consider a keystone jack as a cube consisting of several other uses.

Equipment designed for keystones comes with tiny holes rendered in them instead of including pre-built in jacks. So, users can customize what jacks are incorporated. Moreover, keystones are easy to take out if something needs to be replaced or repaired.

The key benefit of using keystone connectors is versatility. Different types of keystone jacks can be mounted over a single patch panel. Moreover, they can accommodate cables and cords having other numbers of conductors.

The design of a keystone jack shows a kind of Ethernet port at the front. The opening of the jack includes several pins, which are prepared from microns of gold. The opening is available to accept different modular plugs, which are usually unshielded or shielded RJ45 plugs.

Cable types used to connect to Ethernet cables are Cat5e, Cat6, Cat6A, and above. Such category cables are available in patch cables or bulk cable forms.

You will find a punch-down area at the backside of a keystone jack for managing the wires in your cables. These wires are snapped into the contact areas available on the back to establish a connection with your Ethernet cable.

You must follow the appropriate wiring scheme, i.e., t568A or t568B. After the wires are punched down and terminated through a punch-down tool, connecting your keystone jack to one of several different accessories is possible.

Is every keystone jack identical?

Short answer – No; different connection choices are available for keystone jacks. These possibilities enable a broad range of supported options in patch panels and modular wall plates. However, to make them fit into a wide range of such panels, most keystone jacks share a physical shape and size.

Typically, keystone jacks come with a 14.5 x 16mm rectangular face. They include flexible tabs that perfectly retain them and permit them to be physically inserted into compatible patch panels.

Consequently, keystone jacks become almost universally replaceable and interchangeable. They become reusable too. So, it is possible to deal with modular patch panels and wall mounts down to the individual connector and port.

Specific keystone jacks contain a pass-through connector, in which the same port is observed on the front and back. On the other hand, some additional keystone jacks come with a male connector on one side and a female connector on the other.

Some other types still come with a standard port at the front and a hard-wiring cables system at the rear (like punch down blocks). Some different types of keystone jacks allow crimped or soldered connections.

Every keystone, irrespective of the type of jack, is replaceable and interchangeable. So, it offers great flexibility in organizing and mounting several different kinds of electrical jacks in a single panel or plate without needing customized manufacturing.

Certain keystones employ a pass-through type connector, in which a jack is available at the front and rear sides both. Other types only come with a jack at the front and have a unique system for hard-wiring signal cables at the rear.

Examples of keystone jacks include an insulation-displacement connector, a mini 110 block, or a crimp/soldered connection.

Various types of keystone jack:

Though keystone jacks are chiefly used to provide RJ45 Ethernet connectivity, a broad range of various connection options are available for compatible patch panels. The same includes standard patch panel offerings such as RJ45 Ethernet (with different speed and shielding support), fiber optic, and coaxial connections. But, theoretically, they can provide nearly any type of connection possible.

You can find different keystone jacks from reliable manufacturers, including less common types like HDMI 2.1 keystone jacks (with 8K and 4K 120Hz support) and blank keystone jacks (used to isolate unused ports on patch panels and wall jacks).

You can also get RCA jacks, 3.5 mm TRS connectors, speaker terminals, 6P6C RJ11 modular jacks, and 8P8C modular jacks.

There is ample variation in keystone jacks when it comes to specifications and features. Some of them come with gold-plated connectors for better anti-corrosion resistance, whereas others are available in a broad range of colors to differentiate among them when installed properly.

Ethernet RJ45 keystone jacks can too come rated for various speeds in sync with Ethernet cable category ratings. Some of the latest releases provide up to 10 Gigabit Ethernet support for Cat 6a cabling and higher version.

Those keystone jacks which are rated for higher performance will also commonly use thicker copper wiring and possess enhanced per-wire shielding for controlling signal degradation and extra security against crosstalk.

You can find a free punch-down stand from the market with its bigger packs of RJ45 keystone jacks (which can be bought separately), making the punching-down process simpler. But, a punch-down tool is recommended.

When you purchase a keystone jack, it is noteworthy to check whether it comes in high-quality manufacturing or not. So, it is better to buy one made up of fire-retardant plastic, dust caps (for better cable strain relief), and impact-resistant construction standards.

If you need your electric systems to operate efficiently and boost your work productivity, you should choose the appropriate keystone jack. The following section describes various types of keystone jacks along with their functionalities.

Shielded Jacks:

Some people are skeptical when the matter comes to using jacks. Shielded jacks are combined with shielded cables like shielded Cat5e, Cat6, and Cat6A cables. So, it is guaranteed that the shielding against EMI is consistent. Though such keystone jacks are costly, they are recommended for purchase if safety is your priority.

Flush Mount Jacks:

Flush Mount Jacks are the contemporary types of modular jacks currently on the market. They are well-known for establishing efficient connections. They reduce the odds of packet losses and dropped calls because they streamline everything and function in synchronization with your phone.

Once you begin using them, you will perceive that they have enhanced the quality of your electrical connections. Different companies based in USA vend flash mount jacks online. You need to approach the appropriate company and determine the costs for purchases. Also, you can ask the experts for better knowledge about these types of keystone jacks.

Mini Jacks:

Over the last few years, such modular jacks have obtained immense popularity. They are compact, tiny, and very flexible for tight spaces. Whether you want to attend parties or conferences, you can carry such mini jacks anywhere.

The best thing is that they are available at meager prices online. If you want to alter the appearance of these jacks, you can search for relevant add-ons.

Punchdown vs. Coupler:

Keystone jacks are also available based on different types of data, voice, audio, and video connections. It is known that keystones are available in two popular formats, i.e., punch-down and coupler formats. Data and voice data keystones can be either one, whereas video and audio keystones are usually only available as couplers.

The dissimilarity between the two types relates to the way cables are connected at the rear of the keystone jack. Punchdown keystone jacks permit bare wires to be connected to the jack. For permanent installations, directly wiring into a jack is very commonly used.

On the other hand, couplers allow a cable to plug at the rear of the jack (identical to when something plugs at the front side). Such couplers (and the connected cables) can be taken off and replaced effortlessly.

Voice and Data (Telephone and Ethernet) Keystone jacks:

Ethernet jacks are the most significant widespread type. Because every Ethernet cable uses RJ45 connectors, such jacks come in the same size and can be challenging to differentiate.

Certain manufacturers will label the front of the jack as Cat5e, Cat6, etc. However, this is not a universal law. Make sure to go through the description of a keystone jack before purchasing.

Since various versions are available, ethernet keystone jacks can be more complicated than other keystones. If a keystone jack is merely labeled as “keystone,” it is a standard keystone. Certain companies manufacture their own versions of keystones which come in a slightly different size than usual.

The corresponding examples are High-Density Jacks from ICC and Mini-Com Jacks from Panduit. Keep in mind that standard jacks would not fit into equipment that is rated for non-standard jacks and vice versa.

So, if you choose a piece of equipment that uses a non-standard jack, then the remaining of your setup requires to be rated for that similar type of keystone jack.

Telephone keystones are identical to Ethernet, appearing like the downsized versions of that same thing. Like Ethernet, RJ11 and RJ12 are challenging to differentiate by just looking at. So, it would be best if you focused on those product descriptions. Moreover, like Ethernet, certain oddball versions of telephone jacks are available.

Audio and Video Keystone Jacks:

Audio and video keystone jacks encompass several of the most typical audio/video connections currently being used. They are as follows:

• 3.5mm
• F-type
• BNC
• HDMI
• RCA
• Optical Toslink
• S-Video
• Speaker Wire

The majority of these keystones are available only as couplers, except for speaker wire jacks and 3.5mm push pin jacks.

One limitation that keystones pose on audio/video connections is their size. Bigger types of connections like DVI, VGA, and DisplayPort are pretty large to fit over a keystone jack. Generally, users can resolve this by using an adapter to connect a keystone-supported format to the format they need.

For better understanding, for instance, if you want to plug into a DVI monitor, you can install HDMI keystones and then use an HDMI to DVI cable. Those keystones might have limitations, but a little creativity can help you discover a workaround.

Most frequently used keystone jacks:

RJ-11 and RJ-12:

Whenever you want to extend your modem, phone, or phone connection to any room, you need to look for the ideal connectors. These connectors are available in “toolless” varieties. It implies that you can install the wires without soldering any device or without using a screwdriver.

If you are unfamiliar with this, a plastic clamp hinge is available at the rear of the unit, and you can pull it up. At this point, you can snap in wires and then pull them down to firmly secure the cables into the sockets.

These wires showcase different telecom colors. Precisely, two lines, i.e., one long and one short, depict the wire’s color in a particular slot. The color’s long patch shows the primary color, whereas the shorter one represents the stripe color available on a wire. Therefore, it is vital to make sure that you purchase one that offers secure locking and indicates the colors over the slots.

Cat5e Keystone Jacks:

These keystone jacks are suitable for use in Cat5e cabling setups for both domestic and commercial settings. Its construction style is well-known since you need not have to substitute blades while you switch from keystone jacks to patch panels.

Furthermore, termination contacts are made of phosphor bronze of some superior quality. Cat5e keystone jacks provide a lot of strength to the unit and let it sustain punch-downs without breaking off.

If you want to buy a Cat5e keystone jack, you have to make sure that it conforms to the relevant standards, i.e., TIA/EIA 568-B code. If you determine to buy the accepted standard, then it is guaranteed that your unit is robust, long-lasting, and offers excellent performance. Also, it would be best if you ascertained that the keystone jack you purchase comes with proper labeling of both wiring color codes.

Cat6 Keystone Jacks:

Cat6 Keystone Jack is popular for presenting excellent performance in both business and domestic settings. The most important thing to note is that you can purchase these keystone jacks without breaking your bank. You can use them for complex data communication networks in offices and home entertainment systems.

Few of the high-grade varieties of this keystone jack comprise phosphor bronze contacts and strain relief caps. Such references dissipate the physical pressure, allowing the jack to take in punch-downs without breaking.

Furthermore, the contacts securely lock the cables and cords connected to the keystone. So, they make sure that there is zero interruption in signal transmission.

The termination contacts in specific models of Cat6 keystone jacks might also be gold plated. The purpose behind this is to offer extra strength and conductivity. These jacks can be used with unloaded keystone-type wall plates and patch panels, surface boxes, angled multimedia wall plates, and more.

Another interesting thing to note is that these jacks are available in various colors to outfit any specific housing requirement. If you want to purchase such jacks, make sure that the ports on the unit incorporate color codes to guide you while inserting wires. Moreover, you have to make sure that there is a secure locking system for the cables.

Other types of keystone jacks:

In addition to the ones discussed above, you can also come across the following types of keystone jacks:

• 8P8C modular jacks for computer networking
• 6P6C RJ11 modular jacks
• Banana connectors
• Optical fiber connectors
• HDMI jacks
• F connector for TV antenna, satellite, or cable

How to choose a Keystone Jack:

If you take into account the following four aspects, you can easily choose the desired keystone jack:

1. Choice of the category
2. Shielded or Unshielded keystone jack:
3. 90° or 180°
4. Connecting your jack

i. Choice of the category:

From a performance viewpoint, it is crucial to make sure that the category of your keystone jack matches up with your cable. Firstly, you need to figure out which type of cable you would use. The class choice also makes sure that the wires can adequately fit into the contact area.

It can be Cat5e, Cat6, Cat6A, or even Cat8. When you match up the type, you ensure that the cable will perform to its rated specs and capabilities. Note that specific categories are backward compatible with one another. For example, Cat6 cables can be used with Cat5e jacks, whereas Cat5e cables can be used with Cat6 jacks.

When using Cat6A and above, using the cable on lower category plugs is not recommended. So, it is not recommended to use a Cat8 cable on a Cat5e or Cat6A jack. Using a Cat6A cable on a Cat5e or Cat6 jack is not recommended.

ii. Shielded or Unshielded Keystone Jacks:

You need to determine the type of keystone jack based on your setup environment. For most of the installations, the most prevalent choice is an unshielded keystone jack. It is recommended s for everyday use in those areas where EMI (Electromagnetic Interference) is absent.

For example, it can be used in locations like homes and commercial buildings without EMI. The inclusion of a plastic core makes the unshielded keystone suitable for several installations.

If EMI is present in your location, you need to shield keystone jacks. Usually, the shielding on keystone jacks is die-cast aluminum. This shielding works excellently for protecting your network against signal interference.

If you are using a shielded cable, make sure to keep your entire channel shielded. Doing this lets you check the benefits of the shielding inside the cable. Also, this ascertains that each link in your channel stays protected against EMI. It is advisable to follow the structure type of Ethernet cable that you are using when choosing a keystone jack.

iii. 90° or 180° Keystone Jacks:

Jacks are designed in various degrees. The degrees on the jack are related to the way the cable and wires would be inserted into the jack. The two most common degrees you will come across in keystone jacks are 90° and 180°.

These degrees are related to the back end of the keystone module. Because the front of the jack is graded to fit several accessories, the back end could be different for different installs.

The choice of the best angle of the keystone jack relates to the installation location and your preference. Most of the keystone jacks you use would be able to terminate directly into the jack. Hence, selecting either angle depends on your choice.

Occasionally, the cap available on the 180° jack will come with a top opening, and your cable needs to be inserted from the top. It will be a decent choice if you install it into the rear of a patch panel located against a wall. Whichever design you select, keep in mind that there is no speed discrimination between these two angles.

iv. Connecting your Keystone Jack:

It is essential to know where to connect your keystone jack. It’s time to secure your jack after your cable is perfectly terminated and your wires are punched down. The eventual step to do is to select your cable accessories.

It would be best if you planned out cable runs in advance so that you can you where you are going to run the cable. After you determine this, you can choose the type of accessories you will require. Typical accessories connected to a keystone jack are patch panels, wall plates, and surface mount boxes.

A few of the most famous uses for keystone jacks are to connect them into a wall plate or faceplate and patch panels. Usually, keystone jacks are designed such that they easily snap into such accessories.

A wall plate is an accessory to add Ethernet connections to different rooms, buildings, and cubicles. They are easy to mount on the raceway or wall and are worthwhile.

Patch panels help centralize your network in a single location. Frequently, they are observed in server rooms or server closets. Usually, they are designed with 12 to 48 ports. You need not use all the ports in a wall plate. You will connect to the keystone jack that will be connected to the patch panel.

A surface mount box is a portable unit conveniently mounted to furniture or wall. It can contain 1 to 2 keystone jacks based on the box’s size. They help add extra Ethernet connections when required.

Where can you use keystone jacks?

Keystone jacks are built to be used in surface mount boxes, wall plates, and keystone patch panels. Occasionally, they are sold as blank patch panels, which clarifies that you must add your keystone jacks to obtain the same functionality as standard patch panels (they come with non-modular or pre-fitted connectors).

The majority of blank or keystone panels showcase universal sizing. Hence, they can accept major types of keystone jacks. However, slimline patch panels might need tailored keystone jacks designed to provide a trimmer profile.

When purchasing a wall mount or a patch panel for your keystone jacks, check their compatibility with the types you need to use. Also, you need to check the quality marks, such as labeling on the front & back and cable strain relief. This makes it simpler to differentiate between connections and cables and recognize their functionalities.

If you want to mount a keystone patch panel in a specific wall space or rack mount then make sure that it supports your rack size. Alternatively, make sure that its dimensions follow the size and shape of your wall mount space.

Specific mounting hardware for the keystone patch panels is sold separately as well. Check that the one you purchased includes the mounting hardware, or make the additional purchase if required.