Terminating custom Ethernet cables can be a frustrating and tedious task, especially when dealing with the tiny, color-coded wires inside an RJ45 connector. Misaligning a single wire can lead to network failures, wasted connectors, and lost time. Enter the pass-through RJ45 connector—a modern innovation designed to make network cable termination faster, easier, and much more reliable. But what exactly is it, and is it the right choice for your networking project? 

 

Key Takeaways 

  • Flawless Accuracy: Pass-through RJ45 connectors allow individual wires to slide completely through the plug, letting you visually verify your wiring sequence before crimping. 
  • Special Tools Required: To use them properly, you must use a dedicated pass-through crimping tool that cleanly slices off the excess wire flush against the connector face. 
  • Beginner-Friendly: They are highly recommended for DIYers and technicians looking to speed up workflow, reduce wasted connectors, and achieve better cable strain relief. 
  • Not Ideal for Outdoors: Because the freshly cut copper wires are exposed at the very tip of the connector, they are not recommended for outdoor or highly humid environments due to the risk of oxidation and corrosion. 

 

What Is a Pass-Through RJ45 Connector? 

A pass-through RJ45 connector is a specialized Ethernet plug designed with open holes at the front. Unlike traditional connectors, which have a closed end that stops the wires inside the plug, a pass-through connector allows the eight individual twisted-pair wires to pass entirely through the body of the connector. 

 

This design allows the installer to pull the wires tightly through the plug, ensuring the cable jacket is seated deep inside the connector. Once the wiring order is visually confirmed, a specialized crimping tool simultaneously crimps the metal contacts into the wires and slices off the excess wire protruding from the front. 

 

How Does a Pass-Through RJ45 Differ from a Standard RJ45? 

 

The primary difference between a pass-through RJ45 and a standard RJ45 lies in the termination process. 

 

With a standard RJ45 connector, you must measure and trim the eight inner wires to an exact length (usually about half an inch) before inserting them into the plug. If the wires are cut too short, they won't reach the copper contacts. If they are cut too long, the cable jacket won't be secured inside the plug, creating a fragile connection. Furthermore, once the wires are inside a standard plug, it is difficult to see if they have accidentally crossed over one another. 

 

With a pass-through RJ45 connector, precise pre-cutting is unnecessary. You simply untwist the wires, arrange them in the correct standard (T568A or T568B), and push them all the way through the open front of the connector. This guarantees the wires reach the end and allows for a 100% accurate visual inspection before you commit to crimping. 

 

When Should You Use a Pass-Through RJ45 Connector? 

Pass-through connectors are incredibly versatile, but they shine in specific scenarios. You should use a pass-through RJ45 connector if: 

 

  1. You Are a Beginner or DIYer

If you rarely make Ethernet cables, memorizing the color codes and mastering the "trim-and-insert" technique of standard plugs can be daunting. Pass-through connectors remove the guesswork, making it incredibly easy for novices to achieve professional-grade results on their first try. 

 

  1. You Are Working with Thicker Cables (CAT6 or CAT6a)

Higher-category cables feature thicker copper conductors and thicker insulation, making them stiffer and harder to align perfectly in a standard closed-end connector. The pass-through method allows you to pull these stubborn wires through, ensuring a tight, flush fit without them slipping out of order. 

 

  1. You Are Doing High-Volume Installations

For IT professionals and network installers, time is money. Pass-through connectors speed up the termination process significantly. The reduction in mis-crimps and wasted connectors easily offsets the slightly higher cost of the pass-through plugs themselves. 

 

Pros and Cons of Pass-Through RJ45 Connectors 

To make an informed decision, it is important to weigh the advantages and disadvantages. 

 

Pros: 

  • Error Reduction: Visual verification of wire order prevents miswiring. 
  • Better Strain Relief: You can pull the cable jacket deeply into the connector before crimping, resulting in a more durable cable. 
  • Faster Workflow: Eliminates the need to measure and trim wires precisely prior to insertion. 
  • Less Waste: Fewer mistakes mean fewer wasted RJ45 plugs. 

 

Cons: 

  • Requires a Specific Tool: You cannot use a standard crimper; you must invest in a pass-through crimping tool. 
  • Risk of Shorts (PoE): If the crimper blade is dull, microscopic bits of exposed copper may protrude from the end. In Power over Ethernet (PoE) setups running in metal-housed switches, this can potentially cause a short circuit. 
  • Cost: Pass-through connectors are generally slightly more expensive than standard connectors. 

 

How to Terminate a Pass-Through RJ45 Connector 

Terminating a pass-through connector is straightforward. Follow these steps for a perfect connection: 

 

  • Strip the Jacket: Use a stripping tool to remove about 1.5 to 2 inches of the outer cable jacket. 
  • Untwist and Straighten: Untwist the exposed wire pairs and straighten them out completely. (Using the plastic core of the cable or a pen to smooth them helps. 
  • Arrange the Wires: Line up the wires according to your preferred wiring standard (T568B is the most common: white/orange, orange, white/green, blue, white/blue, green, white/brown, and brown). 
  • Insert the Wires: Push the aligned wires into the back of the pass-through connector until they come out of the open front end. 
  • Pull Tight: Pull the exposed wires to slide the connector down until the outer cable jacket is firmly seated inside the back of the plug. 
  • Verify: Look at the wires protruding from the front to ensure the color code is still correct. 
  • Crimp and Cut: Insert the connector into your pass-through crimper. Squeeze the handles firmly. The tool will simultaneously crimp the gold contacts down and shear off the excess wire at the front. 

 

 ShowMeCables offers a wide selection of pass-through RJ45 connectors, Cat5e connectors, Cat6 connectors, Cat6A connectors, shielded Ethernet connectors, crimping tools, Ethernet patch cables, bulk Ethernet cable, and structured cabling accessories for enterprise networking, data centers, and telecommunications installations 

 

 

Frequently Asked Questions (FAQs) 

 

Do I need a special crimper for pass-through RJ45 connectors?  

Yes, you need a specialized pass-through crimping tool. While a standard crimper will push the pins down, it will not cut the excess wire hanging out of the front.  

 

Can pass-through connectors be used for PoE (Power over Ethernet)?  

Yes, pass-through connectors work perfectly well for standard PoE applications. However, for very high-power PoE++ (Type 4) applications, some network engineers prefer standard closed-end connectors to eliminate the risk of electrical arcing from the slightly exposed copper tips, though this risk is generally minimal in standard setups. 

 

Are pass-through connectors worse for signal quality?  

No, pass-through connectors do not degrade signal quality if terminated correctly. In fact, because you can pull the cable jacket deeper into the connector, they often result in better twisting preservation and strain relief.