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.

8D BMA Coaxial | MIL-DTL-38999 III

8D BMA Coaxial | MIL-DTL-38999 III

High-performance MIL-DTL-38999 Series III connectors with integrated BMA coaxial contacts, providing reliable RF signal transmission in demanding aerospace, defence and industrial applications.

✓ 2 Products Available Explore Product Range →
8D Clinch Nuts | MIL-DTL-38999 III

8D Clinch Nuts | MIL-DTL-38999 III

Panel-mount Series III receptacles with clinch nut fixing, offering secure installation, simplified assembly and excellent resistance to vibration and harsh operating environments.

✓ 1 Products Available Explore Product Range →
8D Double Flange | MIL-DTL-38999 III

8D Double Flange | MIL-DTL-38999 III

Double flange receptacles designed for robust panel mounting, delivering exceptional mechanical stability and environmental sealing in demanding aerospace and defence applications.

✓ 28 Products Available Explore Product Range →
8D High Power Contacts | MIL-DTL-38999 III

8D High Power Contacts | MIL-DTL-38999 III

High-current MIL-DTL-38999 Series III connectors engineered for power distribution applications requiring outstanding electrical performance, shielding and durability.

✓ 969 Products Available Explore Product Range →
8D Integrated Backshell | MIL-DTL-38999 III

8D Integrated Backshell | MIL-DTL-38999 III

Series III connectors with integrated backshells that reduce assembly time while improving EMI shielding, cable protection and overall system reliability.

✓ 9 Products Available Explore Product Range →
8D PCB | MIL-DTL-38999 III

8D PCB | MIL-DTL-38999 III

Printed circuit board connectors combining the ruggedness of MIL-DTL-38999 Series III with reliable PCB termination for aerospace, defence and industrial electronics.

✓ 828 Products Available Explore Product Range →
8D Power | MIL-DTL-38999 III

8D Power | MIL-DTL-38999 III

Heavy-duty power connectors designed to handle high current loads while maintaining the environmental protection and reliability expected from MIL-DTL-38999 Series III.

✓ 83 Products Available Explore Product Range →
8D Reinforced Sealing | MIL-DTL-38999 III

8D Reinforced Sealing | MIL-DTL-38999 III

Enhanced sealing connectors providing superior protection against moisture, dust and contaminants for critical applications in extreme operating environments.

✓ 335 Products Available Explore Product Range →
8DV High Vibration | MIL-DTL-38999 III

8DV High Vibration | MIL-DTL-38999 III

Specialist high-vibration connectors engineered to maintain secure electrical connections under continuous shock, vibration and severe mechanical stress.

✓ 253 Products Available Explore Product Range →
8LST Series | MIL-DTL-38999

8LST Series | MIL-DTL-38999

Lightweight circular connectors offering dependable performance, compact design and excellent environmental protection for aerospace and defence applications.

✓ 9 Products Available Explore Product Range →
8LT PCB Contacts | MIL-DTL-38999 I

8LT PCB Contacts | MIL-DTL-38999 I

MIL-DTL-38999 Series I PCB connectors designed for direct board mounting, providing reliable electrical performance in rugged environments.

✓ 9 Products Available Explore Product Range →
8LT Rack and Panel | MIL-DTL-38999 I

8LT Rack and Panel | MIL-DTL-38999 I

Rack and panel connector solutions offering secure mating, high reliability and efficient integration into aerospace and mission-critical equipment.

✓ 6 Products Available Explore Product Range →
8LT Reinforced Sealing | MIL-DTL-38999 I

8LT Reinforced Sealing | MIL-DTL-38999 I

Series I connectors featuring reinforced sealing technology for enhanced protection against moisture, dust and harsh environmental conditions.

✓ 20 Products Available Explore Product Range →
8ST Reinforced Sealing | MIL-DTL-38999

8ST Reinforced Sealing | MIL-DTL-38999

Rugged 8ST connectors with reinforced environmental sealing for maximum protection in demanding military, aerospace and industrial applications.

✓ 6 Products Available Explore Product Range →
8T Backshells | MIL-DTL-38999 II

8T Backshells | MIL-DTL-38999 II

Quality backshells for MIL-DTL-38999 Series II connectors, providing effective cable strain relief, shielding and environmental protection.

✓ 341 Products Available Explore Product Range →
DJLT | MIL-DTL-38999 I

DJLT | MIL-DTL-38999 I

Solder mount MIL-DTL-38999 Series I connectors delivering proven reliability for aerospace, military and harsh environment electrical systems.

✓ 30 Products Available Explore Product Range →
DJT | MIL-DTL-38999 II

DJT | MIL-DTL-38999 II

Robust solder mount Series II connectors designed for dependable performance in demanding military, aerospace and industrial applications.

✓ 48 Products Available Explore Product Range →
Dust Caps | MIL-DTL-38999

Dust Caps | MIL-DTL-38999

Protective dust caps that safeguard unmated MIL-DTL-38999 connectors from dust, moisture and contamination during storage and operation.

✓ 111 Products Available Explore Product Range →
EN3645 | MIL-DTL-38999 III

EN3645 | MIL-DTL-38999 III

European-standard EN3645 circular connectors based on MIL-DTL-38999 Series III, delivering outstanding performance in aerospace and defence systems.

✓ 120 Products Available Explore Product Range →
JN | MIL-DTL-38999 1.5

JN | MIL-DTL-38999 1.5

JN specification connectors offering enhanced performance and interchangeability for aerospace applications requiring MIL-DTL-38999 Series 1.5 compatibility.

✓ 2 Products Available Explore Product Range →
YH38999 | MIL-DTL-38999 IV

YH38999 | MIL-DTL-38999 IV

Next-generation Series IV connectors featuring advanced coupling technology for faster mating, improved durability and reliable harsh environment performance.

✓ 504 Products Available Explore Product Range →
8DS Spacegrade Series | MIL-DTL-38999 Series III

8DS Spacegrade Series | MIL-DTL-38999 Series III

Space-qualified MIL-DTL-38999 Series III connectors designed to meet the stringent reliability and performance demands of satellite and space applications.

✓ 362 Products Available Explore Product Range →
Excess Souriau VAD Assembly Items | 8D Series

Excess Souriau VAD Assembly Items | 8D Series

Browse surplus Souriau VAD assembly components, offering cost-effective solutions for maintenance, repair and specialist connector assembly requirements.

✓ 47 Products Available Explore Product Range →
Sourced D38999 Stock | Various Manufacturers

Sourced D38999 Stock | Various Manufacturers

Access MIL-DTL-38999 connectors sourced from trusted manufacturers, providing alternative supply options for urgent or hard-to-find requirements.

✓ 1 Products Available Explore Product Range →
8STA Series | MIL-DTL-38999 Series

8STA Series | MIL-DTL-38999 Series

Ultra-compact motorsport and aerospace connectors with colour-coded keying, integrated backshells and lightweight construction for high-performance applications.

✓ 59 Products Available Explore Product Range →
8ST Series | MIL-DTL-38999

8ST Series | MIL-DTL-38999

Proven MIL-DTL-38999 circular connectors delivering exceptional reliability, environmental sealing and durability across aerospace, defence and industrial sectors.

✓ 55 Products Available Explore Product Range →
8LT Series | MIL-DTL-38999 I

8LT Series | MIL-DTL-38999 I

Reliable MIL-DTL-38999 Series I connectors combining lightweight construction, scoop-proof contacts and rugged environmental protection.

✓ 18,464 Products Available Explore Product Range →
8T Series | MIL-DTL-38999 II

8T Series | MIL-DTL-38999 II

Bayonet coupling circular connectors offering quick mating, excellent vibration resistance and dependable performance in demanding environments.

✓ 282 Products Available Explore Product Range →
8D Series | MIL-DTL-38999 III

8D Series | MIL-DTL-38999 III

High-density threaded coupling connectors providing exceptional durability, EMI shielding and environmental sealing for mission-critical applications.

✓ 38,274 Products Available Explore Product Range →
8D and D38999 Series III Backshells

8D and D38999 Series III Backshells

Comprehensive range of backshells and cable accessories for MIL-DTL-38999 Series III connectors, supporting strain relief, shielding and cable management.

✓ 240 Products Available Explore Product Range →

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.