Punch Down Tools for Network Cabling

Updated on Apr 3, 2019

A punch down tool, also referred to as krone tool, is a small but primary tool for network technicians to install wiring for telephone, computer and various audio networks. It is widely used to terminate the Ethernet cables by inserting the cables wires into the insulation-displacement connectors (IDC) on the punch down blocks, patch panels, keystone modules, and surface mount of boxes. It works by inserting the wire for a corrosion resistant termination and then trims off excess wire, which ensures fast and precise connections with less effort.

Common Features of Punch Down Tool

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

punch down tool

The dimensions of the punch down tool are not standardized. Some tools have dimensions of 5.35 in x 1.06 in x 1.06 in. Others have 5.25 in x 1.26 in x 1.26 in, 7.00 in x 2.02 in x 2.02 in and so on. Their weights also vary with their sizes. Whatever the dimensions of the punch down tool are, the usage is the same.

Blade types of 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 will be 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 to another pair. however, any pair of clips can be used to connect any two wires.

The A blocks spaced the rows further apart and has been obsolete for many years. The B style is used mainly in distribution panels were 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 blocks 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, 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 connecting on it.

The 110 block is designed for 22 through 26 gauge solid wire. This is the termination used on 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 block 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 system.

How to Use a Punch Down Tool

When it comes to repair or install Ethernet cable, you’ll inevitably need to cut and position wires. Exposed wires can be dangerous and may cause your connections broken. 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: Expose 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 in a counterclockwise motion. Try to straighten the ends as much as you can in order to make them easier to terminate.

Step Three: Place the cable wires in 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.

Place the cable wires in the jack

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

Step Four: Terminate the conductor 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 with 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: Inspect the 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.

Inspect the wires

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.

It looks quite easy to use the punch down tools for network cabling. But only when you strictly follow those steps can you make precise terminations to ensure reliable installations. If you’re looking for a quality punch down tool, please visit www.fs.com.

Related Article: Should We Choose Punch Down or Feedthrough Patch Panel?

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