A punch down tool, also called a punchdown tool or a krone tool (named after the KRONE LSA-PLUS

Krone LSA-PLUS

KRONE LSA-PLUS is an insulation-displacement connector for telecommunications. It is a proprietary European alternative to 110.-History:...

 connector), is a small hand tool

Hand tool

A hand tool is a device for performing work on a material or a physical system using only hands. The hand tools can be manually used employing force, or electrically powered, using electrical current...

 used by telecommunication

Telecommunication

Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...

 and network

Computer network

A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....

 technicians. It is used for inserting wire into insulation-displacement connector

Insulation-displacement connector

An Insulation-displacement connector, insulation-displacement technology/termination or insulation-piercing connector is an electrical connector designed to be connected to the conductor of an insulated wire or cable by a connection process which forces a selectively sharpened blade or blades...

s on punch down blocks, patch panel

Patch panel

A patch panel or patch bay is a panel, typically rackmounted, that houses cable connections. One typically shorter patch cable will plug into the front side, whereas the back holds the connection of a much longer and more permanent cable...

s, keystone module

Keystone module

A keystone module is a standardized snap-in package for mounting a variety of low-voltage electrical jacks or optical connectors into a keystone wall plate, face plate, surface-mount box, or a patch panel....

s, and surface mount boxes (also known as biscuit jacks).

Most punch down tools are of the impact type, consisting of a handle, an internal spring mechanism, and a removable slotted blade. To use the punch down tool, a wire is pre-positioned into a slotted post, and then the punch down tool is pressed down on top of the wire, over the post. Once the required pressure is reached, the internal spring is triggered, and the blade pushes the wire into the slot, cutting the insulation, and securing the wire. For light-duty use, there are also less expensive punch down tools with fixed blades and no impact mechanism.

To accommodate different connector types, 66

66 block

A 66 block is a type of punchdown block used to connect sets of wires in a telephone system. 66 blocks are designed to terminate 22 through 26 AWG solid copper wire....

, 110

110 block

A 110 block is a type of punch block used to connect sets of wires in a structured cabling system. 110 is also used to describe a type of Insulation-displacement connector used to terminate twisted pair cables which uses a similar punch-down tool as the older 66 block...

, BIX

BIX

BIX is part of a telephony cross-connect system created in the 1970s by Nortel Networks. As a system, it consists of various sizes of punch-down blocks, cable distribution accessories , and a punch-down tool to terminate wires at the punch-down block...

and krone require different blades. Removable blades for 66 or 110 are often double-ended, with one end that only inserts the wire for daisy-chain wiring from post to post, and another end that inserts wire and trims the excess length for termination at a post. The trimming blade cutting edge works against the plastic insulating post. Krone blades require a separate scissor-like mechanism for trimming the wire.