D38999 connectors have become indispensible for military, aviation and other rugged applications requiring exceptional durability under extreme conditions. This comprehensive guide provides details on D38999 series, coupling mechanisms, shell style options together with materials, finishes and contact types to consider when selecting the optimal configuration based on operational requirements. Mil Spec 38999 connector guide as below.
Series
Formerly known as MIL-C-38999, D38999 connectors consist of four series – Series I, II, III, and IV. They are environmentally sealed circular connectors utilizing removable crimp contacts, able to operate from extreme temperatures of -65 up to +200°C.
Series I feature a bayonet coupling mechanism and offer high vibration resistance. With scoop-proof inserts, they excel in heavy moisture conditions and are suitable when fast disconnects are needed.
Series II connectors also employ bayonet couplings but do not utilize scoop-proofing. Their low profile, lightweight builds serve well in space/weight constrained applications and in environments with moisture or strong winds but lower vibration levels.
Series III uses a Tri-Start threaded coupling for quick spin-on mating. Scoop-proof and ruggedly built, they satisfy standard mating/unmating cycles including high temperature, vibration or moisture. Series III are ubiquitous in military and aerospace systems.
Series IV leverages a Breech-Lok coupling style optimized for blind mating. Inherently scoop-proof and vibration-hardened, they withstand exposure to high winds and moisture when properly accessorized. Suited for specialized blind mating applications.
In summary, with rugged sealed designs and removable crimp contacts, D38999 connectors reliably serve high-stress applications across industrial, defense and aerospace settings – with the optimal series selection depending on environmental factors, mating needs, weight and space constraints.
| 38999 | Coupling | Scoop Proof | Durability | High Impact Schock | Bend Moment | Price |
|---|---|---|---|---|---|---|
| Series I | Standard Bayonet | Yes | 500 | Yes | 650 lbs in | $ |
| Series II | Low-Profile Bayonet | No | 250 | No | 150 lbs in | $ |
| Series III | Triple Start Threded | Yes | 500 | Yes | 1000 lbs in | $$ |
| Series IV | Breach-Lok | Yes | 500 | Yes – Heavy | 1000 lbs in | $$$ |
Coupling Styles
Multiple coupling styles including threaded, tri-start threaded, bayonet and jam nut are available to enable quick mating and de-mating actions while securing proper interconnection. Tri-start threads allow faster spin-on mating without concerns of axial misalignment. Choose bayonet style for applications needing frequent maintenance while still ensuring vibration resistance.
Shell Styles and Sizes
Shell style impacts shielding effectiveness and grounding reliability. Select from shell style A with grounding fingers, style B mated with conductive couplers or style C for enhanced EMI shielding. Shells are manufactured in standard sizes ranging from 11 to 24+ to match dimensions of component and enclosure cutouts. Metric thread styles are also offered.
Finishes and Materials
Housings crafted from aluminum, stainless steel or high-temperature plastics satisfy weight, cost and durability objectives. Rugged olive drab cadmium, black anodizing, electroless nickel provide corrosion protection while irridite coatings enhance conductivity. Special platings withstand fluid contamination in harsh environments.
Contact Types and Arrangements
Power, coaxial, thermocouple, high-speed signal and fiber optic contacts enable configured connectivity. Scoop-proof barriers prevent misalignments. Many contacts feature removable crimps to enable inspection and replacement. Current capacity ranges from 1 to 40+ Amps. Insert arrangements should optimize density while allowing integration of removable modules, rear inserts, jackscrews and grommet seals suited for application needs. Inserts can be provided pre-wired or unwired.
Keying Position
There are six distinct keying positions available for each shell size in the D38999 series of connectors: N, A, B, C, D and E. The keying position is indicated by the last letter in the part number. A plug will only mate with a receptacle with the same keying code. The following figure shows different keying positions for D38999/26FJ61P plug.
Having 6 different keying positions allows use of up to six D38999/26FJ61P plugs in the same space without the possibility of mating a plug with incorrect receptacle.
MIL-DTL-38999 Specifications and Datasheets
ConntoConn stocks one of the largest inventories of D38999 connectors for immediate delivery including custom configurations. Shop more products Now: D38999 connectors.
For more specifications and datasheets, please contact ConntoConn application engineers at info@conntoconn.com for expert guidance in selecting and tailoring the optimized D38999 connector to improve system reliability even under punishing conditions. Rugged D38999 circular connectors save space while shielding electronics from harsh environments across defense, aerospace and industrial deployments.
