Circular Connectors

Circular connectors are simple yet fundamental components used in a broad variety of applications. They are most commonly found in harsh industrial environments where a robust and secure connection is needed.

RS is an authorized distributor of circular connectors suitable for many industries including aerospace, military, broadcast, and transportation. You can find an extensive selection of products in stock from leading manufacturers such as RS PRO, Amphenol, TE Connectivity, Turck, and Molex.

Browse our range online today, whether searching for popular Amphenol circular connectors, D38999 connectors or another brand or specification. You can also read on to learn more about their benefits, typical applications, and the different types available.

What are circular connectors?

Circular connectors are multi-pin electrical connectors with cylindrical housing. Like most electrical connectors, their purpose is to allow for secure signal and current transmission by joining a male half (i.e. pins) with a female receptacle (i.e. housing). They form a continuous path when connected, whether to power a device, transfer data, or transmit electrical signals. You may also wish to use certain circular connectors to carry a mixed signal.

The body of a circular power connector can be constructed from plastic, various metals, or a mixture of materials depending on its intended application. The contacts are commonly paired with a cable and embedded in insulating material to maintain alignment. Backshells are used to provide physical and electromagnetic protection for the connector and/or cable.

As such, these components are typically designed to perform reliably in harsh environments and are highly resistant to vibration, shock, temperature, pressure, electromagnetic, and radio frequency interference. Pairing contacts with a cable increases their resistance to environmental factors as well as reducing the risk of accidental decoupling.

What are the advantages of circular connectors?

Circular connectors are selected over rectangular connectors for a number of reasons. Often their primary benefit is their capability to perform reliably in environmentally demanding applications.

Their structure offers another practical advantage. By grouping multiple contacts in a compact space, circular connectors save space while allowing for the easy connection and disconnection of cables and devices.

Their other key advantages include:

• Convenience for housing different types of contacts
• Flexibility for housing contacts with different currents due to a wide range of allowable voltages
• Ability to seal in a way that is airtight and insulated or protected from outside factors where a secure connection is required

What are circular connectors used for?

The design and layout of circular connectors can deem them more suitable for some applications than others. Their typical characteristics however make them ideal for use in almost any industrial application where a component may need to withstand damage from harsh environmental factors while providing a secure connection.

Examples of industries requiring this level of robust performance are aerospace, military, machinery, and rail, where miniature high-density D3899 connectors prove especially suited. They are also commonly selected in other fields such as broadcast communication, sound engineering, medical, and energy.

What different types of circular connectors are available?

There are several types of circular connectors with different specifications, while some can be given different names depending on their application. Terms such as circular plastic connectors (CPCs) and circular metal-shell protectors (CMCs) describe the material used for the component housing, with these types commonly designed to mate exclusively with the manufacturers’ own connectors.

Below is an overview of other key variations to look out for:

Military connectors: Also known as MIL-SPEC connectors, military circular connectors are designed to protect the connection from abusive environmental factors common in military and aerospace applications.
DIN connectors: High frequency multi-pin circular connectors designed to meet standards established by the German organization for standardization, Deutsches Institut für Normung.
Micro and nano connectors: Circular connectors with contact pitches of 0.05” and 0.025” respectively.

How to choose the right circular connector:

With such an extensive selection of components to choose from, there are a number of parameters to consider to ensure you select the correct circular connector for your application. These include:

Gender: Connectors can be either male (with pins) or female (with sockets). Pins plug into sockets, so your chosen gender should correspond with what it will be paired with.
Terminals: Termination dictates how conductive elements mate with a connector’s electrical contacts. Options include insulation displacement, solder, wire wrap, tabs, screws, lugs, and crimp.
Mounting method: Circular connectors can mount on cable ends, panels, circuit boards and more. Mounting methods include bulkheads, jam nuts, flanges, and inline cable mounts.
Voltage (V) and current (A) ratings: The maximum voltage and current rating determine the signal a circular connector can safely accommodate, controlled by the size and type of contact used. Low ratings are associated with signaling connectors, while a circular power connector typically has higher ratings.
Contact size: The diameter of a contact or the range of wire gauges that can mate with a contact.
Number of contacts: The number of conductive elements a circular connector has.

Why choose RS for your circular connectors?

RS is a leading authorized distributor of circular connectors in North America. You can find an extensive range of products to suit your requirements, and our world-class service and logistics capabilities mean they can be ready and with you as quickly as possible.

We only stock renowned industry names, so you can rely on each component to meet the highest of standards and provide reliable performance. Whether you are searching for Amphenol connectors or those from the likes of RS Pro or TE Connectivity, you can apply filters to narrow down your options.

You can contact our expert team if you have any questions. Alternatively, head to our content hub for guides, news and more.