20www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
– –
MIL-DTL-38999
Features and Application
Series II
www.conesys.com sales@aero-electric.com
Features and Application
MIL-DTL-38999 Series II connectors feature a bayonet
coupling mechanism with lower profile design and
rear-removable crimp contact retention system.
These connectors were designed for military and commercial
applications where the prime requirements are lower profile
and lighter weight.
Reduction of both size and weight were achieved through
the use of thinner shell walls and length restrictions. These
design restrictions reduced the RFI attenuation characteristics
and the “scoop” protection, while yielding an excellent gen-
eral purpose, lightweight connector. Compared to Series I,
Series II connectors achieve up to 20% reduction in mated
pair length, up to 39% reduction in outside diameter and
up to 40% reduction in weight (128 pin mated pair).
This family of connectors is offered in six receptacle-mounting
styles. They include square flange receptacles, for both front
and rear panel (wall) mounting; square flange receptacles,
for both front and rear panel (box) mounting; square flange
receptacle with extended grommet, for front of panel (box)
mounting; and jam nut receptacles which incorporate
“O” ring seals, designed for rear panel “D” hole mounting.
Plugs are available in two designs, with and without RFI
grounding.
Fifty-two insert arrangement per MIL-STD-1560 are tooled
and qualified to MIL-DTL-38999 Series II, utilizing 3 to 128
M39029 contacts. Contacts come in sizes 22D, 22M, 22, 20,
16 and 12, terminating wire sizes from 28 to 12 gauge.
These connectors are available in wide range of shell materials
and finishes. Aluminum shells are offered in electroless
nickel, bright cadmium, anodized, and olive drab cadmium.
Other finishes such as zinc nickel are available upon request
to commercial callouts only. In addition, we offer passivated
stainless steel 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.
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 same insert
arrangement.
21www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MIL-DTL-38999
Performance Specifications
Series II
– –
Performance Specifications
Operating Temperature Range
Finish B: -65°C to +175°C (-85°F to +347°F)
Finishes C and F: -65°C to +200°C (-85°F to +392°F)
Finish A: -65°C to +150°C (-85°F to 302°F)
Material and Plating Data (Finish)
B – aluminum shell, olive drab cadmium over nickel base
C – aluminum shell, black anodized finish
F – aluminum shell, electroless nickel finish
A – aluminum shell, silver to light iridescent yellow color
(bright) cadmium over electroless nickel base
Corrosion Resistance
Finishes A, B and C withstand 500-hour salt spray.
Finish F withstands 48-hour salt spray.
Durability
Mated connectors withstand a minimum of 250 mating
cycles for RFI plug (MS27484) and 500 cycles for MS27473
and MS27500 plugs.
Environmental Seal
Wired, mated connectors with specified accessories
attached, shall meet the altitude-immersion test specified by
MIL-DTL-38999.
Fluid Resistance
Connectors resist specified immersions in MIL-PRF-7808,
MIL-PRF-23699, MIL-PRF-5606, M2-V Chevron oil, Coolanol
25, MIL-DTL-83133 (JP-8), MIL-DTL-5624 (JP-4, JP-5),
SAE-AMS1424 Type I, and other solvents and cleaning agents.
Voltage Rating
Shell-to-Shell Conductivity
Maximum potential drop shall not exceed:
●With RFI spring fingers, finish F = 1.0 millivolt, while
finishes A and B = 2.5 millivolts.
●Without spring fingers = 200 millivolts.
●Finish C = nonconductive.
Shielding Effectiveness
RFI and EMI attenuation at the specified frequencies meet
the requirements of MIL-DTL-38999.
●RFI shielding effectiveness of mated connectors with
RFI backshells is measured in a triaxial radio frequency
leakage fixture.
●EMI shielding effectiveness is measured at the interface
of mated connectors and tested by the mode-stirred
technique specified in method 3008 of MIL-STD-1344.
Shock and Vibration Requirements
Wired, mated connectors shall not be damaged, nor shall
there be a current interruption longer than one microsecond
when subjected to the following:
Standard Shock
Mated connectors withstand a pulse of approximate half
sine wave of 300 G magnitude with duration of three
milliseconds applied in three axes per MIL-STD-1344,
method 2004.
Vibration
Mated connectors withstand the following vibration levels:
●Random vibration per MIL-STD-1344, method 205 test
condition VI, Letter “J”.
Service
Rating
Suggested Operating Voltage Test Voltage Test Voltage Test Voltage Test Voltage
(Sea Level) Sea Level 50,000 Ft. 70,000 Ft. 100,000 Ft.
AC (RMS) DC V RMS V RMS V RMS V RMS
M 400 550 1300 550 350 200
N 300 450 1000 400 260 200
I 600 850 1800 600 400 200
II 900 1250 2300 800 500 200
Note: The establishment of electrical safety factors is left
entirely to the designer, as he is in the best position to know
exactly what peak voltages, switching currents, transients, etc.,
can be expected in a particular circuit.
22www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MIL-DTL-38999
Part Number Development
Series II
Military and Aero-Electric Part Number Development
– –
Mil. Prefix MS 27473 T 12 B 35 PA
Aero Prefix AE 273 T 12 B 35 PA-340
Shell Type
27472 = Front, wall mount receptacle = 272 (Aero p/n)
27473 = Straight plug = 273 (Aero p/n)
27474 = Jam nut receptacle = 274 (Aero p/n)
27484 = RFI grounding plug = 284 (Aero p/n)
27497 = Rear, wall mount receptacle = 297 (Aero p/n)
27499 = Front, box mount receptacle = 299 (Aero p/n)
27500 = Standard plug with 90˚ backshell = 200 (Aero p/n)
27508 = Rear, box mount receptacle = 208 (Aero p/n)
27513 = Front, box mount rec. (long grommet) = 213 (Aero p/n)
Class
T= With accessory thread (MS27472, 27473, 27474, 27484 & 27497)
E= Same as T in line above except connector is kitted with E-Nut
= No accessory thread, box mount (MS27499 & MS27508)
= No accessory thread, box mount, long grommet (MS27513)
P= Supplied with ring and potting boot (same shell types as “T” class)
Shell Size
8, 10, 12, 14, 16, 18, 20, 22 or 24
Finish (Material & Plating)
A= Aluminum shell, silver to light iridescent yellow (bright) cadmium over electroless nickel base
B= Aluminum shell, olive drab cadmium over electroless nickel base
C= Aluminum shell, black anodized finish (not available in MS27484)
F= Aluminum shell, electroless nickel finish
E= Stainless steel shell, passivated (Aero p/n only, n/a in AE284)
Insert Arrangement
See page 15 thru 19
Contact Designator
P= Pin A= Pin connector less pins (with intent to use non-std pin contacts)
S= Socket B= Socket connector less sockets (with intent to use non-std socket contacts)
Polarization (Keying)
N= Normal (Omitted in part number)
A, B, C, or D(B & C keyways are not available in shell size 8)
Modification (applies to Aero part numbers only)
01 = Less contacts (is not marked on the part)
340 = Connector kitted with M85049/27-XXX E-nut
341 = Connector kitted with M85049/49-2-XXX straight clamp
342 = Connector kitted with M85049/47XXX right angle clamp
Consult factory for other modifications
Note 1: Each connector is furnished with contacts unless
ordered less contacts (L/C) as follows: One spare contact for
inserts requiring 2 through 26 of each contact and two
spares for inserts with 27 or more contacts, and a minimum
of one sealing plug up to 10% of the number contacts. One
insertion/extraction tool for each contact size is also included.
Note 2: Proper part number marking has no “0” in front
of single digit shell size (8) and no “0” in front of single
digit layout. Example of each: J MS27472T8B35S and
J MS27472T10B5S. In both “N” for normal is omitted.
Please note that JAN or J marking is required immediately
in front of MS number.
23www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MS27472
Front, Wall Mounting Receptacle
AE272
Bayonet Coupling, Crimp Removable, Rear Release, Low Profile/Light Weight
– –
G NO. OF TEETH
F ACCESSORY THREAD
4x [ C
MASTER KEYWAY
BLUE COLOR BAND
[ E
[ H
MAX
GROMMET
K GROMMET EXTENSION
.219(5.56)
MIN FULL THREAD
.322(8.18)
.317(8.05)
B
A
MAX .069(1.75)
.058(1.47)
D
MAX
4 MINOR KEYWAYS
Page 22 Completed Part Number
Page 34 Contacts, Sealing Plugs and Tools
Pages 17–19 Insert Arrangements
Page 21 Performance Specifications
Pages 15, 16 Insert Availability and Contact Information
Page 32 Polarization
Shell
Size
A B C D E F G H K
+.010 +.25 Accessory No. of Grommet
Maximum (TP) -.005 -.13 Maximum ±.003 ±.08 Thread Teeth Maximum Extension
inch mm inch mm inch mm inch mm inch mm UNEF-2A inch mm inch mm
8 .828 21.03 .594 15.09 .120 3.05 .932 23.67 .471 11.96 7/16-28 12 .299 7.59 .150/.090 3.81/2.29
10 .954 24.23 .719 18.26 .120 3.05 .932 23.67 .588 14.94 9/16-24 16 .427 10.85 .150/.090 3.81/2.29
12 1.047 26.59 .812 20.62 .120 3.05 .932 23.67 .748 19.00 11/16-24 20 .541 13.74 .150/.090 3.81/2.29
14 1.141 28.98 .906 23.01 .120 3.05 .932 23.67 .873 22.17 13/16-20 24 .666 16.92 .150/.090 3.81/2.29
16 1.234 31.34 .969 24.61 .120 3.05 .932 23.67 .998 25.35 15/16-20 28 .791 20.09 .150/.090 3.81/2.29
18 1.328 33.73 1.062 26.97 .120 3.05 .932 23.67 1.123 28.52 1-1/16-18 32 .897 22.78 .150/.090 3.81/2.29
20 1.453 36.91 1.156 29.36 .120 3.05 .932 23.67 1.248 31.70 1-3/16-18 36 1.022 25.96 .150/.090 3.81/2.29
22 1.578 40.08 1.250 31.75 .120 3.05 .932 23.67 1.373 34.87 1-5/16-18 40 1.147 29.13 .150/.090 3.81/2.29
24 1.703 43.26 1.375 34.93 .147 3.73 1.000 25.40 1.498 38.05 1-7/16-18 44 1.272 32.31 .140/.040 3.56/1.02
24www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MS27497
Rear, Wall Mounting Receptacle
AE297
Bayonet Coupling, Crimp Removable, Rear Release, Low Profile/Light Weight
– –
G NO. OF TEETH
F ACCESSORY THREAD
MASTER KEYWAY
4x [ CBLUE COLOR BAND
[ E
MAX
[ H
MAX
GROMMET
K GROMMET EXTENSION
.219(5.56)
MIN FULL THREAD
B
A
MAX .447(11.35)
.442(11.23)
.069(1.75)
.058(1.47)
D
MAX
4 MINOR KEYWAYS
Page 22 Completed Part Number
Page 34 Contacts, Sealing Plugs and Tools
Pages 17–19 Insert Arrangements
Page 21 Performance Specifications
Pages 15, 16 Insert Availability and Contact Information
Page 32 Polarization Note: See page 33 for panel thickness.
Shell
Size
A B C D E F G H K
+.010 +.25 Accessory No. of Grommet
Maximum (TP) -.005 -.13 Maximum Maximum Thread Teeth Maximum Extension
inch mm inch mm inch mm inch mm inch mm UNEF-2A inch mm inch mm
8 .828 21.03 .594 15.09 .120 3.05 .988 25.10 .547 13.89 7/16-28 12 .299 7.59 .150/.090 3.81/2.29
10 .954 24.23 .719 18.26 .120 3.05 .988 25.10 .672 17.07 9/16-24 16 .427 10.85 .150/.090 3.81/2.29
12 1.047 26.59 .812 20.62 .120 3.05 .988 25.10 .844 21.44 11/16-24 20 .541 13.74 .150/.090 3.81/2.29
14 1.141 28.98 .906 23.01 .120 3.05 .988 25.10 .969 24.61 13/16-20 24 .666 16.92 .150/.090 3.81/2.29
16 1.234 31.34 .969 24.61 .120 3.05 .988 25.10 1.094 27.79 15/16-20 28 .791 20.09 .150/.090 3.81/2.29
18 1.328 33.73 1.062 26.97 .120 3.05 .988 25.10 1.219 30.96 1-1/16-18 32 .897 22.78 .150/.090 3.81/2.29
20 1.453 36.91 1.156 29.36 .120 3.05 .988 25.10 1.344 34.14 1-3/16-18 36 1.022 25.96 .150/.090 3.81/2.29
22 1.578 40.08 1.250 31.75 .120 3.05 .988 25.10 1.469 37.31 1-5/16-18 40 1.147 29.13 .150/.090 3.81/2.29
24 1.703 43.26 1.375 34.93 .147 3.73 1.056 26.82 1.594 40.49 1-7/16-18 44 1.272 32.31 .140/.040 3.56/1.02
25www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MS27499
Front, Box Mounting Receptacle
AE299
Bayonet Coupling, Crimp Removable, Rear Release, Low Profile/Light Weight
– –
4x [ C
MASTER KEYWAY
BLUE COLOR BAND
[ E[ F
MAX
[ H
MAX
GROMMET
.060(1.52)
MAX
GROMMET EXTENSION
.312(7.92)
MAX
.322(8.18)
.317(8.05)
B
A
MAX
.763(19.38)
MAX
.069(1.75)
.058(1.47)
4 MINOR KEYWAYS
Page 22 Completed Part Number
Page 34 Contacts, Sealing Plugs and Tools
Pages 17–19 Insert Arrangements
Page 21 Performance Specifications
Pages 15, 16 Insert Availability and Contact Information
Page 32 Polarization
Shell
Size
A B CEFH
+.010 +.25
Maximum (TP) -.005 -.13 ±.003 ±.08 Maximum Maximum
inch mm inch mm inch mm inch mm inch mm inch mm
8 .828 21.03 .594 15.09 .120 3.05 .471 11.96 .453 11.51 .299 7.59
10 .954 24.23 .719 18.26 .120 3.05 .588 14.94 .578 14.68 .427 10.85
12 1.047 26.59 .812 20.62 .120 3.05 .748 19.00 .703 17.86 .541 13.74
14 1.141 28.98 .906 23.01 .120 3.05 .873 22.17 .828 21.03 .666 16.92
16 1.234 31.34 .969 24.61 .120 3.05 .998 25.35 .953 24.21 .791 20.09
18 1.328 33.73 1.062 26.97 .120 3.05 1.123 28.52 1.062 26.97 .897 22.78
20 1.453 36.91 1.156 29.36 .120 3.05 1.248 31.70 1.188 30.18 1.022 25.96
22 1.578 40.08 1.250 31.75 .120 3.05 1.373 34.87 1.312 33.32 1.147 29.13
24 1.703 43.26 1.375 34.93 .147 3.73 1.498 38.05 1.438 36.53 1.272 32.31
26www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MS27508
Rear, Box Mounting Receptacle
AE208
Bayonet Coupling, Crimp Removable, Rear Release, Low Profile/Light Weight
– –
Page 22 Completed Part Number
Page 34 Contacts, Sealing Plugs and Tools
Pages 17–19 Insert Arrangements
Page 21 Performance Specifications
Pages 15, 16 Insert Availability and Contact Information
Page 32 Polarization Note: See page 33 for panel thickness.
.058(1.47)
4x [ C
MASTER KEYWAY
BLUE COLOR BAND
.317(8.05)
.322(8.18)
[ F
MAX
[ F
MAX
[ E
[ H
MAX
GROMMET
.060(1.52)
MAX
GROMMET EXTENSION
.442(11.23)
.447(11.35)
B
A
MAX
.757(19.23)
MAX
.250(6.35)
MAX
.069(1.75)
4 MINOR KEYWAYS
Shell
Size
A B CEFH
+.010 +.25
Maximum (TP) -.005 -.13 ±.003 ±.08 Maximum Maximum
inch mm inch mm inch mm inch mm inch mm inch mm
8 .828 21.03 .594 15.09 .120 3.05 .471 11.96 .547 13.89 .299 7.59
10 .954 24.23 .719 18.26 .120 3.05 .588 14.94 .672 17.07 .427 10.85
12 1.047 26.59 .812 20.62 .120 3.05 .748 19.00 .844 21.44 .541 13.74
14 1.141 28.98 .906 23.01 .120 3.05 .873 22.17 .969 24.61 .666 16.92
16 1.234 31.34 .969 24.61 .120 3.05 .998 25.35 1.094 27.79 .791 20.09
18 1.328 33.73 1.062 26.97 .120 3.05 1.123 28.52 1.219 30.96 .897 22.78
20 1.453 36.91 1.156 29.36 .120 3.05 1.248 31.70 1.344 34.14 1.022 25.96
22 1.578 40.08 1.250 31.75 .120 3.05 1.373 34.87 1.469 37.31 1.147 29.13
24 1.703 43.26 1.375 34.93 .147 3.73 1.498 38.05 1.594 40.49 1.272 32.31
27www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MS27513
Long Grommet, Front, Box Mount Receptacle
AE213
Bayonet Coupling, Crimp Removable, Rear Release, Low Profile/Light Weight
– –
Page 22 Completed Part Number
Page 34 Contacts, Sealing Plugs and Tools
Pages 17–19 Insert Arrangements
Page 21 Performance Specifications
Pages 15, 16 Insert Availability and Contact Information
Page 32 Polarization
MASTER KEYWAY
BLUE COLOR BAND
.322(8.18)
.317(8.05) .312(7.92)
MAX
.069(1.75)
.058(1.47)
B
A
MAX
.907(23.04)
MAX
.516(13.11)
MAX
4x [ C
[ E[ F
MAX
[ H
MAX
GROMMET
4 MINOR KEYWAYS
Shell
Size
A B CEFH
+.010 +.25
Maximum (TP) -.005 -.13 ±.003 ±.08 Maximum Maximum
inch mm inch mm inch mm inch mm inch mm inch mm
8 .828 21.03 .594 15.09 .120 3.05 .471 11.96 .453 11.51 .299 7.59
10 .954 24.23 .719 18.26 .120 3.05 .588 14.94 .578 14.68 .427 10.85
12 1.047 26.59 .812 20.62 .120 3.05 .748 19.00 .703 17.86 .541 13.74
14 1.141 28.98 .906 23.01 .120 3.05 .873 22.17 .828 21.03 .666 16.92
16 1.234 31.34 .969 24.61 .120 3.05 .998 25.35 .953 24.21 .791 20.09
18 1.328 33.73 1.062 26.97 .120 3.05 1.123 28.52 1.062 26.97 .897 22.78
20 1.453 36.91 1.156 29.36 .120 3.05 1.248 31.70 1.188 30.18 1.022 25.96
22 1.578 40.08 1.250 31.75 .120 3.05 1.373 34.87 1.312 33.32 1.147 29.13
24 1.703 43.26 1.375 34.93 .147 3.73 1.498 38.05 1.438 36.53 1.272 32.31
28www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MS27474
Jam Nut Receptacle
AE274
Bayonet Coupling, Crimp Removable, Rear Release, Low Profile/Light Weight
– –
3 BAYONET PINS
4 MINOR KEYWAYS E THREAD
BLUE COLOR BAND
MASTER
KEYWAY
HEX NUT
PER MS3186
[ F
D
B
FLAT
"O" RING
A
G
MAX.
M ACCESSORY THREAD
H NO. OF TEETH
[ J
MAX
GROMMET
SS 8-22 .150(3.81)
.090(2.29)
SS 24 .140(3.56)
.040(1.02)
.105(2.67)
.084(2.13)
GROMMET
EXTENSION
PANEL THICKNESS
.109(2.77)
.062(1.57)
Page 22 Completed Part Number
Page 34 Contacts, Sealing Plugs and Tools
Pages 17–19 Insert Arrangements
Page 21 Performance Specifications
Pages 15, 16 Insert Availability and Contact Information
Page 32 Polarization
Shell
Size
A B D E F G H J M
+.001 +.03 Jam Nut Thread No. of Accessory
±.005 ±.13 -.006 -.15 ±.016 ±.41 Class 2A ±.003 ±.08 Maximum Teeth Maximum Thread
inch mm inch mm inch mm inch mm inch mm inch mm UNEF-2A
8 .438 11.13 .817 20.75 1.250 31.75 7/8-20UNEF .471 11.96 .937 23.80 12 .299 7.59 7/16-28
10 .438 11.13 .941 23.90 1.375 34.93 1-20UNEF .588 14.94 .937 23.80 16 .427 10.85 9/16-24
12 .438 11.13 1.065 27.05 1.500 38.10 1-1/8-18UNEF .748 19.00 .937 23.80 20 .541 13.74 11/16-24
14 .438 11.13 1.190 30.23 1.625 41.28 1-1/4-18UNEF .873 22.17 .937 23.80 24 .666 16.92 13/16-20
16 .438 11.13 1.320 33.53 1.781 45.24 1-3/8-18UNEF .998 25.35 .937 23.80 28 .791 20.09 15/16-20
18 .438 11.13 1.440 36.58 1.890 48.01 1-1/2-18UNEF 1.123 28.52 .937 23.80 32 .897 22.78 1-1/16-18
20 .464 11.79 1.565 39.75 2.016 51.21 1-5/8-18UNEF 1.248 31.70 .931 23.65 36 1.022 25.96 1-3/16-18
22 .464 11.79 1.690 42.93 2.140 54.36 1-3/4-18UNS 1.373 34.87 .931 23.65 40 1.147 29.13 1-5/16-18
24 .464 11.79 1.815 46.10 2.265 57.53 1-7/8-16UN 1.498 38.05 .984 24.99 44 1.272 32.31 1-7/16-18
29www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MS27473
Straight Plug
AE273
Bayonet Coupling, Crimp Removable, Rear Release, Low Profile/Light Weight
– –
H GROMMET EXTENSION
G
MAX
4 MINOR KEYS
BLUE COLOR BAND
[ F MAX
COUPLING NUT
MASTER KEY
[ A
MIN
SHELL
[ C
MAX
GROMMET
E ACCESSORY THREAD
D NO. OF TEETH
Page 22 Completed Part Number
Page 34 Contacts, Sealing Plugs and Tools
Pages 17–19 Insert Arrangements
Page 21 Performance Specifications
Pages 15, 16 Insert Availability and Contact Information
Page 32 Polarization
Shell
Size
A C D E F G H
No of Accessory Grommet
Minimum Maximum Teeth Thread Maximum Maximum Extension
inch mm inch mm UNEF-2A inch mm inch mm inch mm
8 .337 8.56 .299 7.59 12 7/16-28 .750 19.05 .916 23.27 .150/.090 3.81/2.29
10 .465 11.81 .427 10.85 16 9/16-24 .859 21.82 .916 23.27 .150/.090 3.81/2.29
12 .557 14.15 .541 13.74 20 11/16-24 1.031 26.19 .916 23.27 .150/.090 3.81/2.29
14 .702 17.83 .666 16.92 24 13/16-20 1.156 29.36 .916 23.27 .150/.090 3.81/2.29
16 .827 21.01 .791 20.09 28 15/16-20 1.281 32.54 .916 23.27 .150/.090 3.81/2.29
18 .927 23.55 .897 22.78 32 1-1/16-18 1.406 35.71 .916 23.27 .150/.090 3.81/2.29
20 1.052 26.72 1.022 25.96 36 1-3/16-18 1.531 38.89 .916 23.27 .150/.090 3.81/2.29
22 1.177 29.90 1.147 29.13 40 1-5/16-18 1.641 41.68 .916 23.27 .150/.090 3.81/2.29
24 1.302 33.07 1.272 32.31 44 1-7/16-18 1.766 44.86 .984 24.99 .140/.040 3.56/1.02
30www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MS27484
RFI Grounding Plug
AE284
Bayonet Coupling, Crimp Removable, Rear Release, Low Profile/Light Weight
– –
R.F.I.
GROUNDING
SPRING
4 MINOR KEYS
[ F MAX
COUPLING NUT
MASTER KEY
H GROMMET EXTENSION
G
MAX
BLUE COLOR BAND
[ A
MIN
SHELL
[ C
MAX
GROMMET
E UNEF-2A
ACCESSORY THREAD
D NO. OF TEETH
Page 22 Completed Part Number
Page 34 Contacts, Sealing Plugs and Tools
Pages 17–19 Insert Arrangements
Page 21 Performance Specifications
Pages 15, 16 Insert Availability and Contact Information
Page 32 Polarization
Shell
Size
AC D E F G H
No of Accessory Grommet
Minimum Maximum Teeth Thread Maximum Maximum Extension
inch mm inch mm UNEF-2A inch mm inch mm inch mm
8 .337 8.56 .299 7.59 12 7/16-28 .750 19.05 .916 23.27 .150/.090 3.81/2.29
10 .465 11.81 .427 10.85 16 9/16-24 .859 21.82 .916 23.27 .150/.090 3.81/2.29
12 .557 14.15 .541 13.74 20 11/16-24 1.031 26.19 .916 23.27 .150/.090 3.81/2.29
14 .702 17.83 .666 16.92 24 13/16-20 1.156 29.36 .916 23.27 .150/.090 3.81/2.29
16 .827 21.01 .791 20.09 28 15/16-20 1.281 32.54 .916 23.27 .150/.090 3.81/2.29
18 .927 23.55 .897 22.78 32 1-1/16-18 1.406 35.71 .916 23.27 .150/.090 3.81/2.29
20 1.052 26.72 1.022 25.96 36 1-3/16-18 1.531 38.89 .916 23.27 .150/.090 3.81/2.29
22 1.177 29.90 1.147 29.13 40 1-5/16-18 1.641 41.68 .916 23.27 .150/.090 3.81/2.29
24 1.302 33.07 1.272 32.31 44 1-7/16-18 1.766 44.86 .984 24.99 .140/.040 3.56/1.02
31www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MS27500
Plug with 90° Backshell
AE200
Bayonet Coupling, Crimp Removable, Rear Release, Low Profile/Light Weight
– –
W
L MAX
Y
4 MINOR KEYS
MASTER KEY BLUE COLOR BAND
[ A
MIN
[ F MAX
COUPLING NUT
Page 22 Completed Part Number
Page 34 Contacts, Sealing Plugs and Tools
Pages 17–19 Insert Arrangements
Page 21 Performance Specifications
Pages 15, 16 Insert Availability and Contact Information
Page 32 Polarization
Shell
Size
AF L W Y
Minimum Maximum Maximum Maximum Maximum
inch mm inch mm inch mm inch mm inch mm
8 .337 8.56 .750 19.05 1.859 47.22 1.000 25.40 .828 21.03
10 .465 11.81 .859 21.82 1.859 47.22 1.032 26.21 .891 22.63
12 .557 14.15 1.031 26.19 1.938 49.23 1.094 27.79 1.016 25.81
14 .702 17.83 1.156 29.36 2.125 53.98 1.219 30.96 1.141 28.98
16 .827 21.01 1.281 32.54 2.281 57.94 1.281 32.54 1.255 31.88
18 .927 23.55 1.406 35.71 2.312 58.72 1.344 34.14 1.469 37.31
20 1.052 26.72 1.531 38.89 2.375 60.33 1.375 34.93 1.550 39.37
22 1.177 29.90 1.641 41.68 2.531 64.29 1.438 36.53 1.675 42.55
24 1.302 33.07 1.766 44.86 2.828 71.83 1.719 43.66 1.800 45.72
32www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MIL-DTL-38999
Polarization
Series II
Keying Positions
– –
DATUM F
D°
N°
A°
C°
B°
MASTER
NORMAL
KEYWAY
10°
Notes:
1. Mating face of receptacle shown (plug is opposite).
2. The master keyway (key) has various positions relative to
DATUM F; the minor keyways (keys) remain fixed as
shown. In the Normal position, the master keyway (key)
is 100° from DATUM F.
3. The angles for a given connector are the same whether it
contains pin or socket inserts.
4. The insert arrangement does not rotate relative to master
keyway (key).
Shell
Size
Keying Positions
BSC
N° A° B° C° D°
8 100 82 --118
10 100 86 72 128 114
12 100 80 68 132 120
14 100 79 66 134 121
16 100 82 70 130 118
18 100 82 70 130 118
20 100 82 70 130 118
22 100 85 74 126 115
24 100 85 74 126 115
33www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MIL-DTL-38999 Series II
Flange and Jam Nut Receptacles
Panel Cutouts
Panel Cutouts
– –
A
[ E
4x [ C
FLANGE MOUNT
[ B
MIN
D MAX
PANEL THICKNESS
.109(2.77)
.062(1.57)
PANEL THICKNESS
JAM NUT
F
Note 1: Flange Mounting Dimensions (B cutout and
D MAX) listed only for back of panel mounting (MS27497
and MS27508).
Flange and Jam Nut Mounting Dimensions
Note 2: D MAX includes mounting hardware.
Shell
Size
ABC D E F
+.010 +.25 +.000 +.00
(TP) Minimum ±.005 ±.13 Maximum -.000 -.00 -.010 -.25
inch mm inch mm inch mm inch mm inch mm inch mm
8 .594 15.09 .557 14.15 .128 3.25 .146 3.71 .885 22.48 .830 21.08
10 .719 18.26 .682 17.32 .128 3.25 .146 3.71 1.010 25.65 .955 24.26
12 .812 20.62 .854 21.69 .128 3.25 .146 3.71 1.135 28.83 1.085 27.56
14 .906 23.01 .979 24.87 .128 3.25 .146 3.71 1.260 32.01 1.210 30.73
16 .969 24.61 1.104 28.04 .128 3.25 .146 3.71 1.385 35.18 1.335 33.91
18 1.062 26.97 1.229 31.22 .128 3.25 .146 3.71 1.510 38.35 1.460 37.08
20 1.156 29.36 1.354 34.39 .128 3.25 .168 4.27 1.635 41.53 1.585 40.26
22 1.250 31.75 1.479 37.57 .128 3.25 .168 4.27 1.760 44.70 1.709 43.42
24 1.375 34.93 1.604 40.74 .154 3.91 .168 4.27 1.885 47.88 1.835 46.61
34www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MIL-DTL-38999
Contacts, Tools and Seal Plugs
Series II
Contacts, Plastic Insertion/Removal Tools and Seal Plugs
Crimping and Metal Insertion/Extraction Tools
Contact and Wire Data
– –
Contact
Size
Application Pin Contacts Socket Contacts Seal Plugs Insertion/Removal Tools
Plastic
Type Military No. Military No. Military No. Military No.
22D Power/Signal M39029/58-360 M39029/57-354
MS27488-22-1 M81969/14-01
22M* Power/Signal M39029/58-361 M39029/57-355
22* Power/Signal M39029/58-362 M39029/57-356 —
20 Power/Signal M39029/58-363 M39029/57-357 MS27488-20-1 M81969/14-10
16 Power/Signal M39029/58-364 M39029/57-358 MS27488-16-1 M81969/14-03
16 Coax Coax M39029/76-424 M39029/78-432
12 Power/Signal M39029/58-365 M39029/57-359 MS27488-12-1 M81969/14-04
Contact
Size/Type
Crimp Tool Positioner Positioner Insertion Tool Extraction Tool
For Pin Contacts For Socket Contacts Metal Metal
Military No. Military No. Military No. Military No. Military No.
22D, 22M* M22520/2-01 M22520/2-09 M22520/2-06 M81969/8-01 M81969/8-02
22* M22520/2-01 M22520/2-09 M22520/2-06 M81969/8-03 M81969/8-04
20 M22520/1-01 M22520/1-04 M22520/1-04 M81969/8-05 M81969/8-06
M22520/2-01 M22520/2-10 M22520/2-10
16 M22520/1-01 M22520/1-04 M22520/1-04
M81969/8-07 M81969/8-0816 Coax Inner M22520/2-01 M22520/2-35 M22520/2-35
16 Coax Outer M22520/4-01 M22520/4-02 M22520/4-02
12 M22520/1-01 M22520/1-04 M22520/1-04 M81969/8-09 M81969/8-10
Contact
Size
Test Current Voltage Crimp Well Data Wire Range Finished Wire Range
DC Test Max. Drop Well Dia. Minimum Well Dept Minimum Maximum
Amps Millivolts inch inch mm AWG mm2inch mm inch mm
22D 5.0 73 .0345 ±.0010 .141 3.58 28-22 .08-.33 .030 .76 .054 1.37
22M* 3.0 45 .028 ±.001 .141 3.58 28-24 .08-.20 .030 .76 .050 1.27
22* 5.0 73 .0365 ±.0010 .141 3.58 26-22 .13-.33 .034 .86 .060 1.52
20 7.5 55 .047 ±.001 .209 5.31 24-20 .20-.52 .040 1.02 .083 2.11
16 13.0 49 .067 ±.001 .209 5.31 20-16 .52-1.31 .065 1.65 .109 2.77
12 23.0 42 .100 ±.002 .209 5.31 14-12 2.08-3.31 .097 2.46 .142 3.61
* Inactive for new design
Note 1: Test Current and Maximum Voltage Drop when
tested with silver-plated wire at 25°C.
Note 2: Size 16 coax contacts purchased in bulk.
35www.conesys.com sales@aero-electric.com
MIL–DTL– 38999 S II
MIL-DTL-38999
Contact Installation Instructions
Series II
– –
Contact Installation
Instructions
Crimping Contacts
1. Select the appropriate crimp tool and ensure that the
proper crimp head positioner is used.
2. Cycle the tool to be sure the indentors are open.
3. Determine the correct selector setting for the wire size
from the data plate on the positioner (turret head
assembly) and set the selector knob on the crimp tool
to match.
4. Place the contact, mating end first, into the tool.
5. Insert the stripped wire into the hollow end of the
contact. Be sure the wire is inserted as far as it will go.
6. Close the tool completely to crimp. Unless the tool is
closed completely, the tool will not release the contact.
7. Remove the crimped contact from the tool. Check the
inspection hole to verify that the wire is fully inserted.
Insertion of Contacts
1. Before inserting the contacts, unscrew the accessories
(clamps, backshells or adapters) from rear of plug or
receptacle. Slide the hardware over the wire bundle in
the proper order for reassembly after all the contacts
are inserted.
2. To assist insertion of contacts, lubricate insulator
(grommet) cavities with isopropyl alcohol. Alcohol will
evaporate and will not leave a conductive film. Caution:
Never use any lubricant other than isopropyl alcohol.
3. Place the correct insertion tool on the contact so that the
wire runs along the groove in the tool. (Tool tip will butt
against the shoulder.) Hold the plug or receptacle body
firmly.
4. Beginning with a center cavity, insert the contact into
the insulator with a slow, even pressure until the contact
snaps into position. Make sure the contact and tool are
held perpendicular to the face of the insert during the
contact installation or the grommet could be damaged.
4.1 If contacts are not inserted all the way prior to
removing insertion tool, do not try to reinsert the
insertion tool. Instead, remove the contact and try
again; otherwise reinserting the insertion tool may
damage the inside of the contact cavity.
5. Remove tool and check the face of the connector for
proper contact installation. Proper installation may also
be checked by pulling back lightly on the wire to make
sure the contact is properly seated.
Completion
After all the cavities have been filled, slide the hardware back
into position on the connector and tighten.
Extraction of Contacts (Rework)
1. Slide the hardware back over the wire bundle.
2. Select the appropriate tool. Place the wire into the
extraction tool of the pin or socket.
3. Slowly slide the extraction tool down wire into the contact
cavities until the tool tip bottoms against the contact
shoulder, expanding the clip retaining tines. Hold the
wire firmly in the tool and pull the wired contact and
tool straight out of the rear of the insulator.
Size Pin Contact Socket Contact Basic Crimp Tool Pin Positioner Socket Positioner Insertion/Removal Tool
22D M39029/58-360 M39029/57-354 M22520/2-01 M22520/2-09 M22520/2-06 M81969/14-01
22M M39029/58-361 M39029/57-355 M22520/2-01 M22520/2-09 M22520/2-06 M81969/14-01
22 M39029/58-362 M39029/57-356 M22520/2-01 M22520/2-09 M22520/2-06 M81969/14-01
20 M39029/58-363 M39029/57-357 M22520/1-01 M22520/1-04 Red M22520/1-04 Red M81969/14-10
M22520/2-01 M22520/2-10 M22520/2-10
16 M39029/58-364 M39029/57-358 M22520/1-01 M22520/1-04 Blue M22520/1-04 Blue M81969/14-03
12 M39029/58-365 M39029/57-359 M22520/1-01 M22520/1-04 Yellow M22520/1-04 Yellow M81969/14-04
For coax contacts refer to instructions supplied with contacts.
