Punch Down Tools for Network Cabling

Updated on Mar 13, 2023 by

A punch down tool also referred to as a Krone tool, is a small but primary tool for network technicians to install wiring for telephones, computers, and various audio networks. It works by inserting the wire for corrosion-resistant termination and then trims off excess wire, which ensures fast and precise connections with less effort. This article focuses on ethernet punch down tool types, and explains how to use a punch down tool.


What Is A Punch Down Tool

A punch down tool, which can also be named an RJ45 punch down tool, or Krone tool, is a hand tool widely used to terminate the Ethernet cables by inserting the cable wires into the insulation-displacement connectors (IDC) on the punch down blocks, patch panels, keystone modules, and surface mount of boxes. It is generally composed of three parts: a handle, an internal spring mechanism, and a removable slotted blade.

When you use the punch down tool to press on the Ethernet cable wires pre-positioned into a slotted post on a punch block, an internal spring mechanism will be triggered once the required pressure is reached and the blade pushes the wire into the IDC slot to cut the insulation and secure the wire simultaneously. The punch down blade is not only used to cut the excess wires but also to make the connection between wires and slots.


Common Features of Punch Down Tool

The most common punch down tools available on the market include standard impact tools, universal automatic impact tools, and corrosion-resistant termination tools. A typical RJ45 punch down tool consists of a handle, an internal spring mechanism, and a removable slotted blade. They are typically 6-8 inches long with a blade at one end. The top and bottom of the tools are usually in different colors to help users identify which side is used to cut the wire. Most punch down tools have a changeable blade and a pressure adjustment screw or knob.

Features of Punch Down Tool

Dimensions of punch down tools are not standardized. Some tools measure 5.35" x 1.06" x 1.06". Other tools measure 5.25" x 1.26" x 1.26", 7.00" x 2.02" x 2.02", and so on. Their weight also varies by size. Usage is the same regardless of the size of the punch down tools.


Blade Types of Ethernet Punch Down Tool

To accommodate various connector types, punch down tools have different types of blades with 66 blade or 110 blade. Different blades are used depending on whether you are terminating 66-block or 110-block, which is explained below.

66 Punch Down Block

The 66 block is a type of punch down block used to connect sets of wires in a telephone system. They have been manufactured in three sizes, A, B, and M. A and B have six clips in each row while M has only 4. Each row of a 66 block is set up for one pair of wires to be spliced into another pair. However, any pair of clips can be used to connect any two wires.

The A blocks space the rows further apart and have been obsolete for many years. The B style is used mainly in distribution panels where several destinations (often 1A2 key telephones) need to connect to the same source. The M blocks are often used to connect a single instrument to such a distribution block. 66 blocks are designed to terminate 22 through 26 AWG solid copper wire. 66 block punch down tools are available pre-assembled with an RJ-21 female connector that accepts a quick connection to a 25-pair cable with a male end. These connections are made between the block and the customer premises equipment (CPE).

110 Punch Down Block

As an updated version of 66 block, the 110 punch down block is the core part of the connection management system, used to connect wiring for telephone systems, data network wiring, and other low-voltage wiring applications. 110-type wiring block is flame retardant, injection-molded plastic to do the basic devices and the termination cabling system is connected to it.

The 110 block is designed for 22 through 26 gauge solid wire. This is the termination used on the cat5e patch panel, cat 6 patch panel, and RJ-45 jacks. They are also formed into block type terminations the size of small 66 blocks. The 110 punch down tool is designed for 500 MHz (1 gb/s) or greater bandwidth. 110 blocks are acceptable for use with AES/EBU digital audio at sample rates greater than 268 KHz as well as gigabit networks and analog audio. 110-type wiring block system uses easy quick-fit plug-hop loops which can be simply rearranged, so it provides a convenient cross-connect to non-professional and technical personnel management systems.


How to Use A Punch Down Tool

When it comes to repairing or installing Ethernet cables, you’ll inevitably need to cut and position wires. Exposed wires can be dangerous and may cause your connections to break. Punch down tool thus is necessary to ensure that your wires are secure, and meanwhile to help trim and contain the wires in a basic jack. Then how to use a punch down tool? Just follow the following steps.

Step One: Strip back the cable jacket

What should be noticed is that always leave about 2.5 inches (6 cm) at the end of the cable. Insert the cable into the cable stripping tool or modular crimping tool, and spin it around a few times. Then remove the jacket.

Step Two: Separate the wires

After removing the cable jacket, you will have a few inches of exposed cable. Then gently pull away the wire pairs from the center of the cable so they fan out. Separate the wire pairs by twisting them in a counterclockwise motion. Try to straighten the ends as much as you can in order to make them easier to terminate.

Step Three: Press the wires to the bottom of the jack

Take the protective cover off the top of the jack and set the cable into the block of the jack. Insert each wire into its own separate slot, making sure that the wire matches the A or B configuration. The conductor wires should be extending out of the jack.

Note: Consider choosing between T568A or T568B wiring schemes. The T568B is becoming more popular since it can be used with older color codes as well as newer codes.

Step Four: Cut the wires

Take your punch down tool and press it down on the conductor wires to cut them. The angled part of the blade should contact the long sturdy side of the jack. This will also make sure the wires that are cut are flush with the jack.

Terminate the conductor wires

Step Five: Make sure there are no more extra wires

Check each wire to make sure there is no overhang out the side of the jack. You should also make sure that the edge of the cable jacket is near the base of the jack and the wires you just terminated. The wires should be securely in place. If you notice wires sticking out the side, take a wire cutter and carefully trim the wire so that it’s flush with the jack.

Step Six: Place a dust cap on the jack

Snap the dust caps in place to protect the wires. This will keep the connection secure and can prevent strain on the wires. The dust cap is also very easy to remove: simply pop off the dust cap using a flat-head screwdriver inserted into the indentation on the side.

Note: Fail to set the dust caps back on the jack indicates that your wires may not be seated correctly. It is better to check the wires again and make sure they are secure and trimmed.



Punch down tools are one-handed operation seats and a great helper for your network wiring. By strictly following the steps, you can make precise terminations to ensure the reliable installation of network cabling, as well as save a lot of time in the process of termination.

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