What are Connector Contact Termination Types?

Terminals allow electrical conductors and contacts to meet and continue a circuit, providing a stable yet detachable connection for various cables, sockets, and inlets.

All contact termination types have the same goal: to form an electrical and mechanical connection that transfers the signal as if the circuit was seamless. While some performance loss is unavoidable, efficient contact termination will keep this to a minimum. 

Most cable and panel connectors are available with different contact termination types, which can make it harder to understand which termination style is best for your specific application.

To help you make an informed decision about the right contact termination method, here is a guide to the most common types available from Northern Connectors.

Solder termination

Solder termination is a tried-and-tested method that has been widely used throughout decades of industrial electrical engineering. It involves fusing conductive materials using liquid solder, which hardens to form an electrically efficient connection. The gas-tight joint also acts as an insulator to protect copper conductors against oxidisation.

Being a labour-intensive process, solder termination methods tend to be more suitable for low-volume situations, or for high-density connectors when alternative methods like crimping wouldn’t be possible for the number of contacts.

There are several soldering methods used for contact termination, one of the most popular being dip-solder or through-hole technology (THT). In this case, the contact tail goes through holes in a printed circuit board (PCB) and are soldered in place on the opposite side. This creates a strong mechanical joint and reliable electrical connection. 

Crimp termination

Originally introduced in the 1950s as solderless terminals, crimped termination methods soon became the standard for a consistently reliable performance on the same level as soldering. A gas-tight and corrosion-resistant crimp termination works just as well as a cold-welded connection.

Crimping is a technique that uses specific tools to compress the metal contact around a wire and/or the wire insulation to achieve a symmetrical electrical connection. This is done before inserting the contacts with attached wires into the connector housing. 

With a high level of automation possible, crimp terminations are fast and cost-efficient, ideal for pre-assembly in large volumes. High contact density makes them compact enough for situations with limited space, while the mechanical connection is rugged enough for field use in tough conditions.

There are two main types of wire crimp terminations – open barrel contact and closed barrel contact. Open barrel contacts are stamped from sheet metal then formed into shape for the wire prior to connecting it to the terminal. Closed barrel contacts have a cylindrical opening for the wire, which can be machined into another shape to seal the connection. 

Screw termination

Screw terminals are the oldest connection type in electronics, still used widely across various fields thanks to their robust yet versatile electrical connections. These terminations secure a wire inserted into a receptacle by tightening a built-in screw on the connection-side opening.

They can be operated with a screwdriver instead of requiring specialist tools like crimping, following the principle of a standard terminal block. The tightened screw secures the connecting wires, with some types using a compression plate to avoid damaging the wire.

While they may not be as compact as other types, screw terminations do have the advantage of easy assembly, alteration, or removal of wire connections in the field. Different specifications will have varying maximum torque allowances depending on the cross sections of the wires.

Aside from the classic screw terminal, axial screw contacts are another popular type. These use a conical or tapered spike rather than a traditional screw, which is driven into the middle of the wire to compress the strands evenly against the contact sleeve, typically using a hex key (Allen key). 

Axial screw terminations combine the simplicity of screw techniques with the reduced space requirements of crimp terminations, and are also very effective for large wire gauges.

Clamp termination

Cage-clamp termination mechanisms are quick to assemble and have a high resistance to vibration, providing functional safety with low voltage drops. Not only can they be installed rapidly without the need for special tools, but it’s also easy to fix wiring errors. 

In clamp termination technology, stripped wires are inserted into the connector cavity, then either simply secured with a screw driver or locked into place via an internal mechanism. When the wire is clamped to the contact, the electrical connection is established.

This low-maintenance termination type is commonly used as an alternative to crimping when the tools aren’t available, or in applications where exposure to harsh conditions is a significant factor, including the energy, machining, and robotics industries.

IDC termination

Pierced connections, also known as insulation displacement connections (IDC), are another long-standing form of termination technology. The primary advantage of this technique is that wires don’t need to be stripped of their insulation layer before a connection can be made.

Instead, the connector will have a sharp point, or multiple sharp points, to penetrate through the insulation layer in one smooth step as it’s inserted. This forms a safe gas-tight connection between the conductor and contact without requiring special tools. 

IDC terminations are suitable for solid wires, stranded wires, and ribbon cables, even with small cross sections. They are compatible with automated assemblies, and often used for the mass termination of ribbon cables found in computer systems.

Finding the right connector termination type

Like any component, industrial connectors are available with a wide range of specifications, with the contact termination type being one of the most significant factors when selecting a connector that meets your application requirements. 

The appropriate contact termination styles depend on the type of connector and how it will be mounted, among other characteristics. We supply a large selection of industrial connectors, including common circular, rectangular, and D-sub connectors, so you’re sure to find a model that matches your specifications on our website.

Find out more

When browsing the Northern Connectors website, you can filter by termination type on each category page to narrow down your choices. If you have trouble finding a suitable connector, feel free to call our team of specialists on 01744 815001, or complete our online contact form and we will be in touch at the nearest opportunity.