Features and Application

MIL-DTL-38999 Series I is a bayonet coupling subminiature configuration with high contact density, ideal for smaller wire gauge, general-purpose applications. These environmentresisting connectors are 100% “scoop-proof.” Pins are recessed in elongated shells to prevent the possibility of bending contacts when plugs are scooped into the mating receptacles.

This family of connectors is offered in 5 receptacle-mounting styles. They include square flange receptacles, for both front and rear panel (wall) mounting; square flange receptacles, for both front and rear box mounting; and jam nut receptacles which incorporate “O” ring seals, designed for rear panel “ D” hole mounting.

Standard plugs provide RFI protection by incorporating a continuous strip of attached grounding fingers attenuating interference up to 1 GHz.

Fifty-seven insert arrangements per MIL-STD-1560 are tooled and qualified to MIL-DTL-38999 Series I, utilizing 2 to 128 contacts. Contacts come in sizes 22M, 22D, 20, 16, 12, and 8 (coax and twinax), terminating wire sizes from 28 gauge to 12 gauge including coaxial cable.

These connectors are available in wide range of shell materials and finishes. Aluminum shells are offered in electroless nickel, olive drab cadmium and bright cadmium. Other finishes such as anodic and zinc cobalt are available upon request to commercial callouts only. In addition, we offer passivated stainless steel shells with standard environment-resisting inserts (commercial callouts only), and for highly corrosive environments, nickel-aluminum-bronze shells with standard environment-resisting inserts (commercial callouts only).


Universal I/R Tool – A single, expendable plastic tool is used for both insertion and removal of contacts.

Scoop-Proof Design – Recessed pins in elongated shells minimize the possibility for contact damage. In a blind mating application, mating shells cannot “scoop” the pins, and cause a shorting or bending of contacts.

Closed-Entry Socket Insert – Hard dielectric socket face has lead-in chamfers for positive alignment of pins (even partially bent within pre-established limits) with sockets.

Interfacial Pin Insert Seal – Raised moisture barriers around each pin, which mate into lead-in chamfers of hard face socket insert, provide individual contact sealing. Interfacial seal is never touched by service tools.

Elastomer Wire Sealing Grommet – Sealing over a wide range of wire diameters is assured by a triple wire seal in each cavity at the rear of the connector.

Superior Contact Stability – Rear release crimp contact system features a stamped beryllium-copper retaining clip captivated by molded-in shoulders of each contact cavity in the insulator. A rear-inserted M81969 plastic tool expands the tines beyond the shoulder, releasing the contact.

Shell Polarization – Alternate key/keyway positions prevent cross mating of adjacent connectors having identical insert arrangement.