MIL-DTL-38999 Series I Coding Explained

Part Number Explanation: MIL-DTL-38999 Series I


Below are the explanations for each or the coloured sections of the above part number.

Shell Type

Code Description Available Class
MS27466 Wall Mount Receptacle E*,P,T
MS27467 Straight Plug, EMI grounding E*,P,T
MS27468 Jam Nut Receptacle E*,P,T
MS27469 Hermetic Wall Mount Receptacle Y
MS27470 Hermetic Jam Nut Receptacle Y
MS27471 Hermetic Solder Mount Receptacle Y
MS27496 Box Mount Receptacle E
MS27498 Superseded by MS27467 with M85049/47 backshell E
MS27505 Box Mount Receptacle, rear panel mounting E
MS27515 Superseded by MS27656 E*,T
MS27652 Superseded by MS27466 E*,T
MS27653 Superseded by MS27467 E*,T
MS27654 Superseded by MS27656 E*,T
MS27656 Wall Mount Receptacle, rear panel mounting E*,P,T
MS27661 Straight Plug. lanyard release E*,T
MS27662 Thru-bulkhead Receptacle E
*Inactive for new design. Use Class T.


Class Code Description
E Environmental, may or may not have teeth or rear of shell. Current for MS27496, MS27505, and MS27662. Inactive for new design for all others. Use Class T.
P Potting, includes potting boot and short rear grommet. Inactive for new Air Force design.
T Environmental, with teeth on rear of shell, less rear hardware.
Y Hermetic

Shell Size

The letters A to J must be use for the military part number. These correspond to shell sizes 9 to 25 as follows:

9 11 13 15 17 19 21 23 25


View MIL-DTL-38999 Inserts

Material & Finish

Class Material Finish Temp Range
A Aluminium Bright or gold cadmium over nickel -65°C to +150°C
B Aluminium Olive drab cadmium over nickel -65°C to +175°C
C Aluminium Non-conductive anodise -65°C to +200°C
D Steel Fused tin, class Y only -65°C to +150°C
E Stainless steel Passivated, class Y only -65°C to +200°C
F Aluminium Electroless nickel -65°C to +200°C
N Stainless steel Electro deposited nickel -65°C to +200°C

Contact Arrangement

Contact Style

A Less pin contacts
B Less socket contacts
C Feed through contacts. Used on MS27622 only
H Pin contacts (1500 cycles)
J Socket contacts (1500 cycles)
P Pin contacts (500 cycles), crimp and hermetic with solder cups
S Socket contacts (500 cycles), crimp and hermetic with solder cups
X Pin with eyelet (hermetic only)
Z Socket with eyelet (hermetic only)
Note All shell types (receptacles and plugs) are available with either pin or socket contacts.


Blank No rotation
A View rotation angle (varies by insert)
B View rotation angle (varies by insert)
C View rotation angle (varies by insert)
D View rotation angle (varies by insert)