J599 Series Circular Military Connectors
MIL-DTL-38999 Series III | High-Density Circular Connectors
Product Overview
The J599 Series Circular Connectors are designed and manufactured in compliance with GJB599B (MIL-DTL-38999 Series III) standards, offering exceptional reliability in demanding military, aerospace, and industrial applications. Featuring a triple-start threaded coupling with an anti-loosening mechanism, these connectors provide secure, vibration-resistant electrical connections under extreme operating conditions.
The J599 Series combines compact size, lightweight construction, high contact density, superior EMI shielding, and removable crimp contacts, making it ideal for mission-critical signal and power transmission.
Key Features
- Compliant with GJB599B / MIL-DTL-38999 Series III
- Triple-start threaded quick coupling
- Anti-vibration and anti-loosening mechanism
- Compact and lightweight design
- High-density contact arrangements
- Excellent EMI/RFI shielding
- Removable crimp contacts
- Polarized keying to prevent mismating
- Supports fiber optic, coaxial, and shielded contacts
- Available in aluminum alloy, stainless steel, and titanium alloy shells
- Designed for harsh military and industrial environments
Applications
- Military Electronics
- Aerospace & Avionics
- Naval Systems
- Defense Equipment
- Radar Systems
- Railway Transportation
- Industrial Automation
- Communication Systems
- Test & Measurement Equipment
- Harsh Environment Signal Transmission
Technical Specifications
Mechanical Performance
| Parameter | Specification |
|---|---|
| Coupling Style | Triple-Start Threaded |
| Contact Termination | Crimp, Solder or PCB |
| Mechanical Life | ≥500 Mating Cycles |
| Shock Resistance | 300 g (Half-sine, 3 ms) |
| Sine Vibration | 60 g |
| Random Vibration (High Temperature) | 41.7 g RMS |
| Random Vibration (Ambient Temperature) | 49.5 g RMS |
Materials
| Component | Material |
|---|---|
| Shell | Aluminum Alloy / Stainless Steel / Titanium Alloy |
| Contacts | Gold-Plated Copper Alloy |
| Insulator | Thermosetting or Thermoplastic Plastic |
| Sealing Ring | Silicone Rubber |
Available Surface Finishes
| Finish Code | Description |
|---|---|
| W | Olive Drab Cadmium Plating |
| F | Electroless Nickel |
| K | Stainless Steel Passivation |
| FT | Satin Cadmium Plating |
| TA | Titanium Alloy |
Contact Ratings
| Contact Size | Diameter | Contact Resistance | Rated Current |
|---|---|---|---|
| 22D | 0.76 mm | ≤12 mΩ | 5 A |
| 20 | 1.00 mm | ≤5 mΩ | 7.5 A |
| 16 | 1.60 mm | ≤2.5 mΩ | 13 A |
| 12 | 2.40 mm | ≤1.5 mΩ | 23 A |
| 10 | 3.15 mm | ≤1.0 mΩ | 40 A |
Electrical Performance
| Parameter | Specification |
|---|---|
| Insulation Resistance | ≥5000 MΩ @ 500 VDC |
| Dielectric Withstanding Voltage | Up to 2300 VAC (depending on service class) |
| Contact Material | Gold-Plated Copper Alloy |
| EMI Shielding | Up to 85 dB (100 MHz–1 GHz) |
Service Class Voltage Rating
| Service Class | Sea Level | 21,000 m Altitude |
|---|---|---|
| M | 1300 V | 800 V |
| N | 1000 V | 600 V |
| I | 1800 V | 1000 V |
| II | 2300 V | 1000 V |
Actual voltage ratings vary depending on the contact arrangement.
Fiber Optic & Coaxial Compatibility
Supports installation of:
- Size 20#, 16#, and 12# Fiber Optic Contacts
- Size 12#, 10#, and 8# Coaxial Contacts
- Shielded Contacts
- PCB Contacts
- Crimp Contacts
- Solder Contacts
#8 Dual Coaxial Contact
| Parameter | Specification |
|---|---|
| Bandwidth | 0–20 MHz |
| Rated Voltage | 500 VAC (Sea Level) |
| Rated Voltage @ 21,000 m | 125 VAC |
| Voltage Drop (Inner/Middle Contact) | ≤55 mV @ 1 A |
| Voltage Drop (Outer Contact) | ≤75 mV @ 12 A |
Environmental Performance
| Parameter | Specification |
|---|---|
| Operating Temperature (W) | -65°C to +175°C |
| Operating Temperature (F/K/FT/TA) | -65°C to +200°C |
| Salt Spray Resistance | W: 500 h • K/TA: 1000 h • F: 48/96 h • FT: 96 h |
| Sealing | Qualified to MIL-DTL-38999 III |
| Moisture Resistance | 10 × 24-hour cycles |
| Chemical Resistance | Resistant to fuels, oils, coolants, and solvents |
| Environmental Protection | Rain, Dust, Sand, Humidity, Severe Vibration |
Product Advantages
- Fully compliant with MIL-DTL-38999 Series III
- High-density contact configurations
- Outstanding vibration and shock resistance
- Superior EMI/RFI shielding
- Modular removable contacts
- Long operational life
- Reliable performance in extreme military environments
- Compatible with power, signal, fiber optic, and coaxial applications
- Available in multiple shell materials and protective finishes






