What is RJ45 Connector? Pinout & Types (Shielded, 10-pin)

Last updated on April 5th, 2024 at 01:07 pm

Using RJ45 is an efficient way to achieve high-speed internet on your laptop and computers. Although you can use the Wi-Fi connection on a laptop, this may not give you a higher speed. Also, wireless connections are more vulnerable to connection failures.

Hence wired network connections, like the Local Area Network (LAN) are a much better way to access the Internet. This article will cover all the details on RJ45 and some common FAQs related to it.

What does RJ in RJ45 mean?

The ‘RJ’ in RJ45 stands for Registered Jack. RJ standard is widely used for Ethernet at WiFi routers, modems, etc. It is even used as the connection interface for voice and data communication. The ‘45’ after RJ denotes the number of interface standards in the cable.

What does 45 in RJ45 mean?

4 in ‘RJ45’ signifies that it has 4 pairs of cables. To decrease the capacitance formed by the closely spaced cables, 5 twists per inch are provided to the cable. Hence the number 45 in ‘RJ45’.

What is RJ45 connector?

What is RJ45 connector?
RJ45 connector

It is a plastic cap that fits at one end of the Ethernet wire. It has 8 small pins inside to connect 8 wire pieces. It comes with a lock port, which ensures a fixed connection with the port in your laptop or computer. Thus, it prevents the accidental removal of the Ethernet cable from the port.

To remove the Ethernet cable from the laptop/computer port, one must press the connector lock first and then pull it outside the port.

The RJ45 connectors fall under the category of modular connectors. It uses modular connectors and 50-pin miniature connectors. These connectors were invented by Bell Labs labs in 1973 and were first used in the United States for the Universal Service Ordering Code (USOC).

RJ45 connector pinout

An RJ45 connector is connected to an RJ45 cable (Ethernet cable). Based on the standard of RJ45 cable, it can either be T568A or T568B.

RJ45 T-568A pinout

RJ-45 T568A connector pinout
RJ-45 T568A connector pinout

As shown in the figure above, T-568A consists of 8 wires. The order of wiring is White-Green, Green, White-Orange, Blue, White-Blue, Orange, White-Brown, Brown.

RJ T-568B pinout

RJ-45 T568B connector pinout
RJ-45 T568B connector pinout

T-568B also consists of 8 wires. But the order of wiring is White-Orange, Orange, White-Green, Blue, White-Blue, Green, White-Brown, Brown.

Different types of RJ45 connectors

Different types of RJ45 connectors
Different types of RJ45 connectors

As per the applications, different types of RJ45 connectors are available in the market. These are listed below:


RJ45 Standard Connector
RJ45 Standard Connector

These are the commonly used 8P8C (8-position 8-connection) RJ45 connectors. It is a non-shielded type connector.


Shielded RJ45 connector
Shielded RJ45 connector

These are also called RJ48 connectors. They fall under the category of shielded connectors and consist of internal shielding as well as shielded wires.


Rugged RJ45 connectors
Rugged RJ45 connectors

These are highly reliable connections as they have a provision to protect the connected devices. Thus, they are called Hi-Rel connectors in short.

10 Pin

10 pin RJ45 connector
10-pin RJ45 connector

These connectors are used in serial line applications.


Minature RJ45 connector
Miniature RJ45 connector

These connectors are a miniature version of the standard RJ45 connectors.

RJ45 Crimping Tools

Crimping tool
Crimping tool

The twisted-pair cables are attached to the connector using a crimping tool. It creates a perfect connection that is not affected by other electric connections or moisture. This tool presses the connecter over the wires with a high force in such a way that the wires are permanently sealed to the connector.

The crimping tool connects the Ethernet cables with the male connectors very easily. The same tool can be utilized to cut the wires, strip off the insulation, and bend the wires. As per the requirement, there are different tools available in the market. Some of them are

  • Hand-operated crimping tools
  • Electric crimping tool
  • Hydraulic crimping tool, etc.


Are RJ45 and CAT6 the same?

The RJ45 is an interfacing standard (used for connectors), while CAT6 is the sixth category model of twisted-pair cables. Hence they are not the same.
Sometimes, the cables used for Ethernet connectors are referred to as RJ45 cables. But the standard has nothing to do with the cable. It is a standard for connectors. The cables used with connectors are mentioned as RJ45 cables for easy understanding.

Are the RJ45 cables used in Ethernet connections alone?

These cables are most commonly used in Ethernet connections. But it has several other applications like:
1. Automation systems
2. Process control systems
3. Fabrication and assembly of Industrial robotic arms
4. Measurement systems
5. Quality Control
6. Voice Over Internet Protocol (VOIP) Devices
7. Internet of Things (IoT) Devices

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Blessy C Simon

I'm an AI researcher who enjoys writing. Whether it's crafting compelling blog posts, or optimizing web content for search engines, I have a knack for tailoring my writing style to suit various niches and audiences.

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