J599 Series I (D38999 I series )features: 3‑point bayonet quick‑lock, sealing, EMI shielding, blind‑mate capability, high vibration and shock resistance.
GJB part numbers are prefixed with JY27XXX, while MIL‑DTL‑38999 part numbers are prefixed with MS27XXX. They are fully interoperable and interchangeable.
Distinction of the Five Series‑I Receptacles (Core: mounting configuration is defined by the numerical segment in part number)
| GJB Model |
MIL‑DTL‑38999 Model |
Description |
Mounting Style |
Shell Category |
Application Scenarios |
| JY27466 |
MS27466 |
Wall‑mount square flange receptacle |
Front‑panel mounting: install from outside of equipment panel, secured by 4 flange screws |
Class T (with rear‑end thread for backshell mounting) |
Mounted on outer surface of chassis, front‑panel installation, most widely used; plug mating accessible from exterior |
| JY27656 |
MS27656 |
Wall‑mount square flange receptacle |
Rear‑panel mounting: feed‑through from inside chassis toward panel cutout, fasten screws from interior |
Class T |
Assembly from chassis interior; only mating face exposed externally, flange screws invisible from outside |
| JY27496 |
MS27496 |
Box‑mount square flange receptacle |
Box‑type flange, front‑panel mounting with thicker flange profile |
Class E (no rear‑end thread, incompatible with standard backshell) |
For box / module housing, internal potting sealing, no shielding backshell applied |
| JY27505 |
MS27505 |
Box‑mount square flange receptacle |
Box‑type flange, rear‑panel mounting |
Class E |
Box‑style module, assembled from chassis interior, for potting sealing |
| JY27468 |
MS27468 |
Jam‑nut receptacle |
Single circular cutout, secured by lock nut, no square flange |
Class T |
Space‑constrained applications, only circular panel cutout required; sealing capability available |
Wall‑mount type (27466 / 27656): Thin square flange, Class‑T shell with rear‑end external threads for fitting shielding backshells. These two types are selected for the vast majority of projects.
27466: Fastened by screws from the outer panel side (front‑panel mounting).
27656: Fastened by screws from inside the chassis (rear‑panel mounting).
Box‑mount type (27496 / 27505): Reinforced thick‑wall flange, Class‑E shell without rear‑end threads. Incompatible with standard metal backshells. Mostly used for potting sealing and rarely applied to ordinary chassis panels.
Jam‑nut mounting type (27468): No square flange. Features external shell thread plus lock‑nut fastening. Only a circular cutout is required on the panel, intended for space‑limited applications.
