RJ45 Pass-Through Modular Plugs – Simple and Controlled Cable Termination

What is the difference compared with a conventional RJ45 plug?

With a conventional RJ45 modular plug, the individual conductors are arranged according to the required pin assignment, cut to the appropriate length and then inserted together into the plug. As the conductor ends are subsequently located inside the plug, their correct order and even positioning must be ensured before insertion.

With a Pass-Through plug, the conductors can instead be pushed through the openings provided at the front of the plug. The protruding conductor ends initially remain visible.

This makes it possible to check that the conductors are arranged in the correct order before crimping. During the subsequent crimping process, the contacts are pressed into the conductors and – when using a suitable Pass-Through crimping tool – the protruding conductor ends are cut flush at the front of the plug.

What are the advantages of the Pass-Through principle?

A key advantage is the simplified handling during cable termination. The individual conductors do not have to be precisely cut to their final length before they are inserted into the plug. They can first be fed through the plug and then trimmed together.

At the same time, the conductor order remains visible until immediately before crimping. This makes it easier to check the required wiring and can help identify pin assignment errors at an early stage.

The Pass-Through principle is therefore particularly practical when network cables are regularly terminated on site or when custom cable lengths are required.

How does termination work?

First, the outer jacket of the network cable is stripped to the length required for the plug being used. The individual conductors are then prepared and arranged according to the required RJ45 pin assignment.

The arranged conductors are inserted together into the Pass-Through plug. Unlike with a closed modular plug, they are fed further through the plug body until their ends protrude from the front.

The conductor arrangement can now be checked again to ensure that the conductors are correctly positioned and run completely through the designated guides. The plug is then crimped using a crimping tool suitable for Pass-Through plugs. During this process, the plug contacts are pressed into the conductors. With suitable tools, the conductor ends protruding from the front are simultaneously cut flush with the plug.

Use the appropriate crimping tool

A crimping tool specifically designed for this type of plug should be used for Pass-Through modular plugs. Such a tool not only crimps the plug but usually also includes a cutting function for the conductors protruding from the front.

This allows contact termination and trimming of the conductors to be carried out in a single operation.

However, the manufacturer's specifications should always be checked to ensure that a particular plug is compatible with the crimping tool being used.

Pass-Through does not automatically mean higher network performance

The Pass-Through principle primarily describes the design and termination method of the modular plug. On its own, it does not indicate a higher transmission speed or better electrical performance.

The transmission characteristics of a terminated network connection depend on factors including the cable and plug used, their respective category and specifications, and correct installation.

It is therefore important to use an RJ45 plug that is suitable for the cable and intended application and to observe the relevant manufacturer's specifications.

In summary

RJ45 Pass-Through modular plugs simplify the manual termination of network cables by allowing the individual conductors to be fed completely through the plug. The conductor arrangement therefore remains visible and can be checked before crimping. With a suitable Pass-Through crimping tool, the contacts are crimped and the protruding conductor ends are cut flush.

Compared with conventional RJ45 modular plugs, the main advantage is therefore not inherently higher transmission performance, but simple, clear and controlled termination.