MIL-DTL-38999 Connectors

MIL-DTL-38999 connectors - military specification hermetically sealed circular connectors designed and manufactured to mil 38999 specification
Overview MIL-DTL-38999 Connectors
By Staff Writer Last updated: January 4th, 2024

MIL-DTL-38999 connectors are a type of circular connector and a vital component in the defense sector, designed to be robust and provide reliable, secure optical and electrical connections. 

These circular connectors are standardized under the military specification MIL-DTL-38999, defining a variety of configurations to meet the wide range of requirements that come with defense operations.

The 38999 connector is produced in different series, including the widely used Series III. They have a high-density design, accommodating different contact sizes and layouts, such as a large number of contacts in limited space.


The connector outer shells are generally manufactured out of robust materials such as stainless steel or aluminum, aiding resistance to unforgiving conditions, such as mechanical stress or contact with dust and moisture. 

A further central characteristic of D38999 connectors is hermetic sealing, which can prevent the equipment becoming contaminated and maintains the performance of any connected electronic devices. The electrical performance of the connectors themselves is also key, supporting a range of signal types like data, power, and RF. 

To meet the Mil 38999 specifications, connectors require thorough environmental testing, including but not limited to vibration and temperature extremes. The ability to function effectively is important in maintaining the standard of versatility required in defense applications, which can range from avionics and radar systems to communication equipment and electronic warfare.

As a result, interoperability is crucial, with 38999 connector manufacturers designing the connectors work with those made by other manufacturers, ensuring consistency in the equipment and aiding replacement or maintenance.


Applications of the 38999 connector extend to ground-based communication infrastructure, naval vessels, and a wide variety of other defense platforms. In all of these, reliable connectivity is vital for operational success.

For example, these connectors provide secure and reliable connections for critical systems in aircraft, which can have high vibration and temperature fluctuations. Adhering to the specifications contributes to the safety and efficiency of defense operations.