Thanks to its high level of expertise on MIL-DTL-38999 SERIES I, II & III, V & EN3645 connectors, Amphenol Socapex is the industry leader in D38999 circular connectors. Offering QPL MIL-DTL-38999 and EN3645 qualified connectors with a large range of features including 38999 Rack & Panel, 38999 Miniature, 38999 Reduced Flange, 38999 Stand-off, 38999 Integrated Backshell & 38999 Power, Amphenol Socapex can answer all your needs through its line of reliable & qualitative products. Our 38999 connectors are available in Aluminum, Stainless Steel, Marine Bronze or Composite material with ROHS-compliant plating available in Black-Zinc Nickel and more. While the qualified Mil-Spec versions offer you a number of features, our customizable options are endless. We also provide free D38999 Series III CAD files.
What is MIL-DTL-38999?
MIL-DTL-38999 is a military-grade circular connector standard designed for high-reliability cable-to-panel applications in military, aerospace, and harsh industrial environments. This specification outlines four key 38999 connector series:
- Series I: Bayonet coupling – Amphenol’s LJT series
- Series II: Low-Profile Bayonet coupling – Amphenol’s JT series
- Series III: Tri-Start ACME Thread – Amphenol’s TV-CTV series
- Series IV: Breech-Lock
These high-performance circular connectors ensure superior resistance to environmental stress, making them ideal for mission-critical applications.
What is a D38999 connector?
A D38999 connector refers to the MIL-DTL-38999 Series III family, known for its rugged thread-coupling design. The part numbering system for these military circular connectors always begins with D38999/.
Key features of D38999 Series III connectors include:
- Tri-Start ACME thread coupling for secure locking
- 100% scoop-proof design to prevent contact damage
- Metal and composite shell options for weight and corrosion considerations
- EN3645 standard compliance for European aerospace applications
These mil-spec connectors are widely used in aviation, defense, and high-reliability industrial systems.
Do D38999 connectors come with contacts?
Yes, D38999 connectors can be ordered with or without contacts. Some part number examples include:
- D38999/26A35PN – Includes pin contacts
- D38999/26A35SN – Includes socket contacts
- D38999/26A35AN – No pin contacts included
- D38999/26A35BN – No socket contacts included
What is the MIL-C-38999 standard?
The MIL-C-38999 standard, now superseded by MIL-DTL-38999, defines high-performance circular connectors designed for rugged applications such as military, aerospace, and industrial environments. These mil-spec connectors provide robust cable-to-panel I/O connectivity and come in four distinct series:
- Series I: Bayonet coupling – Amphenol’s LJT series
- Series II: Low-Profile Bayonet coupling – Amphenol’s JT series
- Series III: Tri-Start ACME Thread – Amphenol’s TV-CTV series
- Series IV: Breech-Lock
These D38999 connectors are engineered for extreme durability, ensuring resistance to vibration, moisture, and high temperatures.
What is a D38999 in-line connector?
A D38999 in-line connector is a specialized military circular connector that features a cable-to-cable connection rather than a cable-to-panel setup. Unlike standard D38999 receptacles, these connectors lack a flange for panel mounting.
For example, Amphenol’s designation for an in-line D38999 connector starts with TV01 or TVS01, offering flexible connectivity solutions in harsh environments.
Is MIL-C the same as MIL-DTL?
Yes, MIL-C-38999 has been superseded by MIL-DTL-38999. This transition ensures a more detailed specification for military-grade circular connectors, maintaining reliable cable-to-panel I/O solutions for aerospace, defense, and industrial sectors.
The D38999 connector series includes:
- Series I: Bayonet coupling – LJT / HE308 / MIL-DTL-38999 Series I
- Series II: Low-Profile Bayonet coupling – JT series
- Series III: Tri-Start ACME Thread – TV-CTV series
- Series IV: Breech-Lock
These military connectors are designed for high vibration resistance, corrosion protection, and extreme durability.
Connectors ordered without contacts will still be marked with P or S codes, per MIL-DTL-38999 specifications.
How do I choose a circular connector?
Selecting the right circular mil connector depends on several factors:
- Number of contacts & electrical requirements – Determine current and voltage ratings.
- Environmental conditions – Consider temperature range, sealing, vibration, and salt spray resistance.
- Mating style – Choose from threaded (Tri-Start), bayonet, push-pull, or blind-mate connectors.
- Available space & weight constraints – Consider metal vs. composite shells.
For expert guidance, consult a technical support team specializing in D38999 connectors.
What are the three types of MIL-DTL-38999 connectors?
The three primary series of D38999 military circular connectors are:
- Series I: Bayonet coupling – Amphenol’s LJT series
- Series II: Low-Profile Bayonet coupling – Amphenol’s JT series
- Series III: Tri-Start ACME Thread – Amphenol’s TV-CTV series
Each series is optimized for specific applications, ensuring superior performance in military, aerospace, and rugged industrial environments.
What are rugged connectors?
Rugged connectors, including D38999 circular connectors, are designed for harsh environments where durability and reliability are critical.
Features include:
- Corrosion-resistant materials (stainless steel, aluminum, composite)
- Sealing against moisture, dust, and extreme temperatures
- High resistance to shock and vibration
- Secure locking mechanisms (Tri-Start thread, bayonet, push-pull)
These military-grade connectors are widely used in defense, aerospace, marine, and industrial applications.
What is the military standard for connectors?
Military connectors must meet strict standards such as MIL-DTL-38999, ensuring high reliability in extreme conditions. These mil-spec circular connectors are essential in mission-critical applications across defense, aerospace, and industrial sectors.
For power, signal, and data applications, D38999 connectors provide the ultimate performance in high-vibration, high-temperature, and moisture-exposed environments.
