What Is an IDC Socket?

Insulation-displacement connector (IDC) sockets are sockets that use cold-welded wires placed in the socket’s head. The number of wires that can be placed in an IDC socket range from six to 64, and there is always an indicator on the socket’s head showing where the first wire must go. IDC socket heads are used in telecom and networking, and allow operators to swap out wires and change wiring configurations with relative ease. This was first made for single wires but evolved into connecting multiple wires into the socket head.

When an IDC socket clamps down on a set of wires, it cold-welds them to the socket head, meaning it makes a tight connection such as with welding, but without any heat. Cold-welding is done through vacuum pressure, and the connection between the socket and wires is gas-tight. The head contains little blades that cut through the wire’s plastic insulation and allows for interfacing with the internal wire. This allows the socket block to use the power from the wires in whatever device has a connection.

The amount of wires, and the spacing between the wires, differs for each IDC socket. The common range of wires goes from six to 64, with the larger end of the spectrum being used on network cables. By using these socket blocks, users can create their own ribbon cables, but a manufacturer often puts the wires together. IDC sockets are meant to be one-use but, if users are able to carefully extract wires without damaging them, then the socket can be used more than once.

IDC sockets are most commonly seen in telecom and networking industries. Home use is exclusive to phone jack connections, where small IDC heads are used. The classic image of a large server with hundreds of colored wires connected into different sockets and jacks is how IDC sockets are typically used. This allows network and telecom operators to inject a large number of wires while saving space and making the area neater than if all the wires were connected individually.

All IDC socket heads have some sort of indicator to show where the first wire should go. With some, a red wire is used as the first wire but, since many connections use several red wires, this indication is less common. More commonly, there is a raised V or triangle to show where the first wire has to go. Ignoring this placement will cause the IDC socket to function improperly.