Mil-DTL 38999 II Connectors
Mil-DTL 38999 II Connectors
Key Features
- Compact low-profile shell design helps reduce installation space in aerospace and defense systems
- Reliable 3-point bayonet coupling enables fast and secure mating in high-vibration environments
- High-density insert arrangements support up to 128 contacts for space-constrained applications
- Designed for dependable electrical and mechanical performance in harsh operating conditions
- Available in multiple shell materials and plating options for corrosion resistance and environmental durability
- Operating temperature range from −65°C to +175°C for demanding aerospace and military applications
- Environmental sealing helps protect against moisture, fluids, dust, and other contaminants
- Compatible with standard MIL-DTL-38999 Series II configurations including MS27472 and MS27497 styles
- Gold-plated copper alloy contacts provide stable conductivity and reliable long-term mating performance
- Supports signal, power, coaxial, twinax, and PCB tail contact configurations for flexible system integration
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MIL-DTL-38999 Series II Circular Connectors
Product Overview
MIL-DTL-38999 Series II (JT Series) circular connectors are compact, lightweight military circular connectors designed for high-density interconnect applications where space and weight matter. As a result, engineers widely use them in aerospace, avionics, tactical communications, naval electronics, and other defense systems that demand dependable electrical performance in harsh environments.
Series II connectors use a quick three-point bayonet coupling system that enables fast and secure mating, even under high vibration. In addition, the shorter shell profile saves installation space when compared with larger scoop-proof connector designs. Therefore, equipment designers can simplify layouts and improve packaging efficiency in compact electronic systems. Overall, Series II connectors combine reliability, performance, and reduced size in one practical interconnect solution.
Advantages of MIL-DTL-38999 Series II Connectors
Low-Profile Shell Design for Space-Constrained Systems
MIL-DTL-38999 Series II connectors feature a compact shell design that reduces overall connector length and rear-panel clearance requirements. Consequently, they fit well in applications where installation space remains limited, especially in aerospace and defense equipment.
The smaller shell profile simplifies system packaging in avionics modules, UAV payload systems, missile electronics, and other high-density assemblies. In addition, reduced connector size can lower cable assembly weight, which is particularly important in airborne and portable systems.
Rapid 3-Point Bayonet Coupling System
Series II connectors use a three-point bayonet locking mechanism for quick mating and secure retention. Moreover, the 120-degree coupling design allows faster installation while maintaining stable electrical performance during vibration and movement.
Because of these advantages, military and aerospace engineers frequently select this coupling style for systems that require fast maintenance, reliable locking, and easy handling during field operation.
Technical Performance Specifications
| Feature | Specification |
|---|---|
| Shell Sizes | 9, 11, 13, 15, 17, 19, 21, 23, 25 |
| Contact Arrangements | Up to 128 contacts |
| Contact Sizes | 8, 12, 16, 20, 22D, 22M |
| Coupling Style | 3-Point Bayonet |
| Termination Types | Crimp, PCB Tail, Solder |
| Operating Temperature | −65°C to +175°C |
| Shell Materials | Aluminum Alloy, Stainless Steel |
| Available Finishes | Olive Drab Cadmium, Electroless Nickel, Black Zinc Nickel |
| Insulation Resistance | 5,000 MΩ Minimum |
| Mating Durability | 500 Cycles Minimum |
Advanced Materials & Shell Finishes
MIL-DTL-38999 Series II connectors are available with several shell materials and plating options to support different environmental and performance requirements.
Engineers commonly select Electroless Nickel (Class F) for aerospace and avionics systems because it delivers strong EMI shielding performance and temperature resistance. Meanwhile, Olive Drab Cadmium (Class B) remains a standard military finish for corrosion protection in harsh outdoor environments.
For RoHS-compliant applications, Black Zinc Nickel provides strong corrosion resistance without cadmium. In addition, stainless steel shells support marine, offshore, and chemically aggressive environments where systems require additional durability and long-term reliability.
Cross-Reference & Intermateability Support
Our MIL-DTL-38999 Series II connectors support cross-referencing with major military and commercial connector series, including Amphenol JT, Souriau 8LT/8T, and ITT Cannon KJ connectors.
Available configurations include standard military part numbers such as MS27472 wall mount receptacles, MS27473 straight plugs, MS27474 jam nut receptacles, and MS27497 wall mount receptacles. Therefore, engineers can simplify replacement projects and reduce redesign work when upgrading existing systems.
In addition, alternate keying positions help prevent incorrect mating in applications that require higher connection security.
Contact Arrangements & Insert Options
MIL-DTL-38999 Series II connectors support a wide range of insert arrangements for signal, power, and mixed-contact applications. For example, available options include standard signal contacts, power contacts, coaxial contacts, twinax contacts, and PCB tail configurations.
Gold-plated copper alloy contacts provide reliable conductivity and stable mating performance in demanding environments. As a result, engineers commonly use these connectors in both high-density signal systems and rugged power distribution applications.
Typical Applications
MIL-DTL-38999 Series II circular connectors are commonly used in aerospace and avionics equipment, tactical communication systems, naval electronics, radar systems, rugged embedded electronics, and military vehicle platforms.
Because of their compact size and vibration-resistant coupling design, these connectors perform especially well in applications where installation space remains limited but reliable performance is still critical.
Engineering Support & Technical Resources
We support both prototype and production projects with connector cross-referencing, part number identification, insert arrangement selection, and BOM matching assistance.
In addition, we provide 3D CAD models in STEP, IGES, and Parasolid formats to simplify system integration and product development. We also deliver customized cable assembly and interconnect solutions based on specific project requirements.
Request a Technical Review & RFQ
Need help selecting a compatible MIL-DTL-38999 Series II connector?
Send us your part number, drawing, BOM, or application details, and our team will review your requirements and provide quotation support within 24 hours. Whether you are replacing an existing connector or developing a new system, we are ready to help you identify the right solution quickly and efficiently.
Frequently Asked Questions
What is the difference between MIL-DTL-38999 Series II and Series III?
Series II connectors use a compact bayonet coupling design for faster mating and reduced size, while Series III connectors use a threaded triple-start coupling system with scoop-proof protection for higher mechanical strength.
Are MIL-DTL-38999 Series II connectors interchangeable with Amphenol JT connectors?
Many Series II connectors are designed to intermate with Amphenol JT and equivalent military-standard connector configurations.
What industries commonly use Series II circular connectors?
Series II connectors are widely used in aerospace, military, avionics, naval systems, tactical communications, and rugged industrial electronics applications.
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Strict Production Process
Engineers develop optimized electronic circuits and structural designs based on real application needs.
High-quality components and materials are carefully selected from trusted suppliers to ensure long-term reliability.
Automated SMT and precision soldering technologies are used to build stable and high-performance circuit boards.
Sensor elements or connector terminals are assembled with the PCB and housing to ensure accurate operation and strong mechanical stability.
Each product undergoes strict calibration and functional testing to guarantee accuracy and stable performance.
Every unit is carefully inspected, labeled, and securely packaged to ensure it arrives safely and performs reliably for your applications.
Strict Production Process of Yafeite
