MIL-DTL-38999

MIL-DTL-38999 is an internationally recognized connector series designed for demanding applications where high reliability, ruggedness, and compact design are critical.

Widely used in defense, aerospace, offshore, and industrial sectors, it has been one of the most established standards for electrical and optical connections in harsh environments for decades

The connectors are available in several series (I, II, III, and IV), with Series III being the most commonly used. This series features a tri-start bayonet coupling that enables fast and secure mating, combined with excellent resistance to vibration and shock. It also offers strong environmental protection against moisture, dust, and corrosion, and is available in a variety of materials and finishes, including aluminum, composite, and stainless steel.

One of the major advantages of the D38999 series is its modularity. It supports a wide range of inserts and termini, including electrical, data, and fiber optic options. This allows for a standardized interface across multiple technologies and use cases, offering flexibility and simplified logistics.

Fiber Optic Contacts

For fiber optic applications, D38999 Series III can be equipped with EB16 expanded beam termini from TE Connectivity or standard fiber termini for applications where low insertion loss or specific compatibility is required.

Features:

Available in singlemode or multimode
Choose between EB16 expanded beam for rugged field use or standard ferrule termini for low loss
High mechanical durability and long lifespan
Easy to clean and maintain
Ideal for defense, offshore, broadcast, and industrial environments

Benefit:
Expanded beam optics offer high resistance to dust and dirt, while standard ferrule termini provide lower insertion loss and high precision in clean environments. This flexibility allows one connector interface to adapt to various environments and performance needs.

Copper Contacts

D38999 Series III is also available for purely electrical connections, used for power, signal, or data. These versions support a wide variety of inserts and pin layouts tailored to specific requirements.

Features:

Supports both power and data transmission
Compatible with modern high-speed interfaces (Ethernet, USB, coax)
Same rugged housing and bayonet coupling as fiber versions
Available in multiple material and plating options

Benefit:
Using the D38999 platform for both power and signal enables a standardized solution with excellent resistance to vibration, shock, dust, and corrosion.

Hybrid Fiber and Copper

For systems requiring both data and power in a single connector, hybrid versions of D38999 Series III are available. These combine fiber optic and electrical termini in the same connector shell.

Features:

Combines EB16 expanded beam with electrical pin/socket inserts
Supports simultaneous transmission of fiber, signal, and power
Reduces the need for multiple connectors and cables
Maintains full MIL-DTL-38999 compatibility

Benefit:
The hybrid solution provides maximum flexibility and space savings. It enables the integration of both communication and power in one rugged connector – ideal for mobile systems, sensor units, and field installations.