Circular Connectors & Assemblies
Browse our extensive range of circular connectors from leading manufacturers, including Eaton Souriau, Yeonhab, Fujikura, and more. Designed for aerospace, defence, motorsport and demanding industrial applications, our range includes Series I, II, III and IV connectors, backshells, accessories and custom interconnect solutions.
Frequently Asked Questions About Circular Connectors
Choosing the right circular connector involves much more than simply matching the number of contacts. Factors such as environmental sealing, coupling style, shell size, contact arrangement, current rating and EMI protection all influence long-term reliability. The FAQs below answer some of the most common questions engineers and purchasing teams ask when selecting circular connectors for aerospace, defence, industrial and harsh environment applications.
Shell size determines the physical dimensions of the connector, while the insert arrangement defines the number, size and layout of contacts. When selecting a connector, consider the available installation space, required current capacity, signal types and future expansion. Many MIL-DTL-38999 connectors are available with dozens of insert arrangements to accommodate mixed power, signal, coaxial and fibre optic contacts.
Military-specification (MIL-Spec) connectors, such as the MIL-DTL-38999 and MIL-DTL-5015 series, are manufactured to rigorous defense standards ensuring interoperability, extreme temperature tolerance, and resistance to environmental hazards. Industrial circular connectors offer similar locking mechanisms (bayonet, threaded, push-pull) tailored for commercial cost efficiency and automation machinery.
Choosing the correct coupling mechanism depends on your application’s space constraints and vibration levels. Threaded connectors offer extreme vibration resistance, Bayonet coupling provides fast 1/4-turn locking with visual alignment, and Push-Pull mechanisms are ideal for high-density panels requiring quick single-handed operation.
Many circular connectors are designed for harsh environments and offer excellent resistance to dust, moisture, vibration, salt spray and temperature extremes. When correctly assembled with compatible backshells and cable glands, many connector families provide IP-rated sealing suitable for demanding aerospace, defence, marine and industrial applications.
Electromagnetic interference (EMI) can reduce signal quality and system reliability. Metal-bodied circular connectors, conductive finishes and screened backshells help maintain electrical continuity and minimise interference. This makes them ideal for avionics, communications equipment, radar systems and other sensitive electronic applications.
Although fully interchangeable within their respective specifications, each series uses a different coupling mechanism. Series I connectors feature bayonet coupling, Series II offers an improved bayonet design with faster mating, while Series III uses threaded triple-start coupling for exceptional vibration resistance and environmental sealing. The correct series depends on your application's installation requirements and operating environment.
Yes. Many circular connector families support mixed layouts containing power, signal, coaxial, twinax, triax, thermocouple and fibre optic contacts within the same connector. This allows designers to simplify wiring while reducing connector count and overall system weight.
Integrated backshell connectors combine the connector body and cable termination into a single assembly. They reduce assembly time, improve cable strain relief and often provide enhanced EMI shielding. Integrated backshells are particularly popular in aerospace and defence systems where reliability, weight reduction and simplified installation are priorities.
High-power circular connectors are designed to carry significantly higher currents than standard signal connectors. They're commonly used for power distribution, electric propulsion, vehicle systems, industrial machinery and military equipment where compact size must be combined with excellent mechanical durability and environmental sealing.
Circular connectors are widely used throughout aerospace, defence, motorsport, rail, marine, medical, industrial automation, energy and communications industries. Their combination of secure locking mechanisms, high contact density and excellent environmental performance makes them suitable wherever dependable electrical connections are essential.
