Applications of Circular Connectors
Our MIL-DTL-38999 III series circular connectors are ideal for circuit signal connections in various industries.
Environments
Our MIL-DTL-38999 III series circular connectors are designed to thrive in environments characterized by strong vibrations, heavy rain, sandstorms, and high humidity.
General Information
- Compliant with MIL-DTL-38999 III series standards
Three-start thread for fast and secure mating, equipped with anti-loosening mechanism
Compact size, lightweight design, and high contact density
Superior EMI shielding capabilities
Removable contacts for easy installation and anti-misinsertion features, preventing bent pins
Designed for high-strength vibration and harsh environmental conditions, including strong winds, sand, and humidity
12# and 16# contact arrangements support fiber optic contacts
12#, 10#, and 8# contact arrangements support coaxial and shielded contacts
Main Technical Performance
Mechanical Performance
- Shell materials: Aluminum alloy, stainless steel, titanium alloy
- Insulator materials: Thermosetting or thermoplastic
- Sealing material: Silicone rubber
- Plating options:
- Class W: Cadmium plating
- Class F: Chemical nickel plating
- Class K: Stainless steel passivation
- Class FT: Aluminum alloy with matte cadmium plating
- Class TA: Titanium alloy
- Contact materials: Gold-plated copper alloy, available in crimp, solder, and printed circuit board configurations
- Mechanical lifespan: 500 mating cycles
- Shock resistance: Withstands 3ms half-sine wave with peak acceleration up to 300g
- Vibration resistance:
- Sinusoidal vibration: 60g with temperature cycling and simulated attachments (36 hours)
- Random vibration at high temperatures: Frequency range of 100-1000Hz, power spectral density of 1g²/Hz, corresponding to an RMS value of 41.7g
- Random vibration at ambient temperature: Frequency range of 100-1000Hz, power spectral density of 5g²/Hz, corresponding to an RMS value of 49.5g
Environmental Performance
- Temperature range:
- Class W: -65°C to +175°C
- Class F, K, FT, TA: -65°C to +200°C
- Salt spray test results:
- Class W: 500 hours
- Class K, TA: 1000 hours
- Class F: 48 hours/96 hours
- Class FT: 96 hours
- Sealing: Complies with MIL-DTL-38999M low-pressure impregnation requirements
- Humidity resistance: According to MIL-DTL-38999M, 24 hours with 10 cycles
- Fluid resistance: Resistant to various fuels, coolants, and solvents
Electrical Performance
Withstanding voltage (V):
Service rating M N I II Sea level 1300 1000 1800 2300 21000m 800 600 1000 1000
Note: Different contact arrangements have different operating levels, see top-right corner of contact arrangement label
Contact resistance and current rating:
Contact ID Diameter (mm) Resistance (mΩ) Current (A)
22D Ø0.76 ≤12 5 20# Ø1.00 ≤5 7.5 16# Ø1.60 ≤2.5 13 12# Ø2.40 ≤1.5 23 10# Ø3.15 ≤1.0 40
- Insulation resistance: ≥5000MΩ under normal conditions (500VDC)
- Insulation resistance: ≥5000MΩ under normal conditions (500VDC)
- Class W: ≤2.5mΩ
- Class F, FT: ≤1.0mΩ
- Class K, TA: ≤10mΩ
- EMI shielding: Minimum attenuation of 85dB from 100MHz to 1GHz (Class F, Class W)
- EMI shielding: Minimum attenuation of 65dB from 1GHz to 10GHz (Class F), 50dB (Class W)
- 8# twin coaxial contacts: Frequency bandwidth of 0-20MHz, maximum rated voltage of 500VAC, 125VAC at 21000 meters
- Voltage drop: Inner and middle contacts ≤55mV at 1A, outer contacts ≤75mV at 12A
