Rhino Mil-DTL-38999 Series III circular connectors

Standard MIL-DTL-38999 Series III connectors typically carry multiple signal or low-power contacts, whereas Rhino 38999 connectors are specialised for high-power transmission with a single large contact. They use the same shell size and threaded coupling system as regular 38999 connectors for mechanical compatibility, but internally they feature a unique single-pole power contact (RADSOK) designed for very high current. In short, Rhino 38999 provides the MIL-38999 form factor optimised to handle hundreds of Amps, far beyond the current of standard 38999 inserts.

The high current capability is achieved through the RADSOK® hyperbolic contact technology used in Rhino 38999 connectors. The socket contact is a twisted, spring-grid design that creates a large surface area around the mating pin. This design spreads the electrical contact over multiple points, lowering contact resistance and improving heat dissipation. As a result, a single RADSOK contact can safely conduct very high currents (on the order of hundreds of Amps) without overheating, which is key to the Rhino 38999’s 1000 A rating.

Safety is built into the Rhino 38999 connector design. First, the connectors feature IP2X finger protection, meaning the live power contact is recessed and shielded to prevent an accidental touch by fingers or tools when the connector is unmated. Second, the safe mating design ensures that the connector’s shell engages and aligns properly before the power contact mates, preventing arcing or misalignment under load. Together, these features protect users and equipment when connecting or disconnecting high-power lines.

Rhino 38999 connectors come in several mechanical configurations to suit different installations. You can get them as square-flange receptacles (panel mount), jam-nut receptacles (rear or front mount with a single locking nut), or inline connectors for cable-to-cable mating. They also offer various backshell options – including straight and 90° angled backshells with EMC shielding – to accommodate cable routing and electromagnetic shielding needs. Importantly, the Rhino series retains the standard MIL-DTL-38999 Series III panel cut-out dimensions and mounting thread, so they can drop into existing 38999 mounting holes and patterns, simplifying integration into legacy systems.

The Rhino 38999 series is designed with flexible termination options. Depending on the specific connector variant, you can terminate the high-current contact by traditional crimping (for high-gauge wires), by using a bolt-on lug (eyelet) onto the contact for heavy cable lugs, or by connecting to a bus-bar interface. This versatility means you can integrate the connector with large power cables or solid busbar systems, whichever is appropriate for your power distribution design. All termination methods are engineered to maintain low resistance and high reliability under extreme current.

These connectors are built for harsh environments. They are sealed to IP68 when mated (water-tight at depth) and even IP69K in many configurations, meaning they withstand high-pressure water jets and wash-down. The standard shell materials (aluminium, stainless steel, etc.) and plating (such as black zinc-nickel) provide excellent corrosion resistance – for example, up to 500 hours salt spray endurance with the RoHS-compliant zinc-nickel finish. Rhino 38999 connectors also function across a broad temperature range (typically -55 °C to +125 °C, with short-term peaks up to +150 °C), and they resist shock and vibration per military standards. This ruggedness makes them suited to military vehicles, aircraft, naval systems, offshore platforms, mining equipment – essentially any setting with extreme temperature, moisture, or mechanical stress.

Rhino 38999 connectors find use in any application that demands very high current in a tough, compact interface. Typical examples include military and defence systems (such as armoured vehicles and field power units), aerospace platforms (for instance, in aircraft or satellite power distribution), hybrid and electric vehicles (connecting battery packs, drive motors, or fast-charging systems), and industrial/off-highway equipment (like mining trucks, locomotives, and drilling rigs). They are also employed in critical infrastructure – for example, on communication towers or base stations – where reliable high-power delivery is essential. In all these cases, Rhino connectors provide a secure and standardised way to connect high-current power feeds in harsh conditions.

Mechanically, the Rhino 38999 shares the MIL-DTL-38999 Series III shell style, but electrically and functionally it is a unique single-pole system. A Rhino 38999 plug will only properly mate with a corresponding Rhino 38999 receptacle, because the insert arrangements and contact sizes are specific to this high-power design. They are not intermateable with standard multi-pin 38999 connectors – if you tried, the contacts and keying would not align. Therefore, to use Rhino connectors, both sides of the connection need to be Rhino 38999 components (though you can mix different mounting styles, e.g. a jam-nut plug with a flange receptacle, as long as they are the Rhino series). This dedicated pairing ensures the high-current performance and safety features are preserved in the connection.