MIL-DTL-38999 Series II

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Lightweight, Low-Profile Bayonet Coupling for Space-Constrained Applications

Elimec USA offers the MIL-DTL-38999 Series II connectors—optimized for military and aerospace applications requiring a compact, lightweight solution. These connectors feature a bayonet coupling mechanism, rear-removable crimp contacts, and a low-profile design, making them ideal for environments where space and weight are at a premium.

 Key Advantages

• Up to 40% Weight Reduction
  Compared to Series I, Series II connectors offer up to 20% shorter      length, 39% smaller outer diameter, and 40% lighter weight,      while maintaining excellent performance.
• Rear-Release Contact System
  A robust crimp contact design with a stamped beryllium-copper retaining clip ensures secure connections and easy maintenance using a standard M81969 plastic tool.
• Flexible Mounting Options
  Offered in six receptacle styles, including square flange and jam nut      types, for both front and rear panel or box mounting.
• Closed-Entry Socket Inserts
  Chamfered dielectric inserts align even slightly bent pins, preventing damage and ensuring accurate mating.
• Moisture & Environmental Protection
  Includes interfacial seals around each pin and triple-sealing elastomer grommets for wire sealing—providing excellent resistance to fluids and harsh conditions.
• Shell Polarization
  Key/keyway design prevents mismating with adjacent connectors having the same insert layout.

Insert & Contact Details

• Insert Arrangements: 52 per MIL-STD-1560
• Contact Range: 3 to 128 M39029 contacts
• Contact Sizes: 22D, 22M, 22, 20, 16, and 12
• Wire Range: 28 AWG to 12 AWG

Material & Finish Options

• Aluminum Shells:
  • Finish B: Olive drab cadmium over nickel (500-hour salt spray)
  • Finish F: Electroless nickel (48-hour salt spray)
  • Finish A: Bright cadmium over electroless nickel
  • Finish C: Black anodized (500-hour salt spray, nonconductive)
• Stainless Steel Shells:
  Passivated shells available for commercial applications requiring enhanced corrosion resistance.

Electrical Performance

• Shell-to-Shell Conductivity:
  • With RFI springs:
    • Finish F: ≤ 1.0 mV
    • Finish A/B: ≤ 2.5 mV
  • Without springs: ≤ 200 mV
  • Finish C: Nonconductive
• Shielding:
  RFI/EMI shielding effectiveness meets MIL-DTL-38999 standards, tested via triaxial and mode-stirred methods.

Environmental & Mechanical Performance

• Operating Temperature:
  • Finish B: –65°C to +175°C
  • Finish C/F: –65°C to +200°C
  • Finish A: –65°C to +150°C
• Durability:
  • 250 mating cycles (with RFI plug MS27484)
  • 500 mating cycles (plugs MS27473, MS27500)
• Sealing:
      Connectors meet altitude-immersion test requirements when mated and accessorized per MIL-DTL-38999.
• Fluid Resistance:
  Resists common aviation and industrial fluids including MIL-PRF-5606, JP-8, JP-5, MIL-PRF-23699, and others.
• Shock & Vibration:
  • Shock: 300G, 3 ms pulse in 3 axes per MIL-STD-1344
  • Vibration: Random vibration per MIL-STD-1344, Method 2005, Condition VI, Letter "J"

Looking for a compact, lightweight connector for your defense or aerospace project?
Elimec USA can help you integrate the right MIL-DTL-38999 Series II configuration.
Contact us for technical assistance or a custom quote.