D38999 Series III Connectors

d38999 series iii conesys
D38999 series iii circular connector

D38999 Series III circular connectors are high-performance cable to panel interconnects making them suitable for military, aerospace and harsh environment applications. NYKCS is a fully approved value-add distributor (VAD) for Conesys. Therefore, we can assemble MIL-DTL-38999 III connectors to meet your specific requirements. Contact us today for the best price and fast delivery.

The MIL-DTL-38999 Series III  range of military connectors (commonly known as D38999 III) features a number of body styles, contact termination options, body materials and platings. Consequently, these connectors suit a wide variety of electronic, mechanical and environmentally demanding applications. Up to 128 contacts are available in a number of defined high-density insert arrangements with a reliable tri-start coupling.

Price and delivery

We are the most competitively priced supplier of approved MIL-DTL-38999 Series III connectors. NYKCS is fully approved to AS9100 Rev D and can assemble to meet your requirements. Contact us now for fast turnaround in 48 hours from receipt of order.

Conesys MIL-DTL-38999 Series III

Product Features

  • Scoop proof crimp contacts
  • Triple start mating thread
  • One full turn to mate
  • Full mate indicator
  • Keying options
  • Industry standard contact arrangements
  • EMI shielding to 65dB minimum at 10 GHz

Product Benefits

  • High density in a rugged package
  • Reliable fast mating
  • Self locking with visual confirmation
  • Improved shielding compared to bayonet variants
  • Massive range of accessories
D38999 Series III plug zinc

Value-Add Assembly

Value Add Assembly AS9100In-house assembly in the UK enables NYKCS to supply a huge range of approved connectors quickly and efficiently. Thereby meeting each customer’s specific requirement for MIL-DTL 38999 Series III.

Fast turnaround of finished product is available from an extensive UK stock holding ensuring shortest delivery times, best price and no minimum order quantity of approved product.

d38999 series iii connectors

Data Sheets

Conesys MIL-DTL-38999 Series III SpecificationConesys MIL-DTL-38999 Series III Specification

MIL-DTL-38999 Series III Connectors Product SheetMIL-DTL-38999 Series III Connectors Product Sheet

AS85049 Product SheetAS85049 backshells for MIL-DTL-38999 Series III Product Sheet

M39029 Contacts Product SheetM39029 contacts for MIL-DTL-38999 Series III Product Sheet

MIL-DTL-38999 Series III Contacts Crimp Tool ReferenceCrimp Tool Reference

Quality Approvals

Conesys Franchised Distributor CertificationConesys Franchised Distributor Certification

DLA 38999 Documentation - VQP-18-031857DLA 38999 Documentation - VQP-18-031857

Part Number Breakdown Tables

The Part Builder and tables below will assist you to construct an official mil-spec part number for a MIL-DTL-38999 series III connector. Many of the connector OEM’s have their own proprietary part numbers which we can cross-reference to and from the mil part numbers. 

Part Number Builder


  1. enter a part number (E.g. 26ZJ90SN) to see the component makeup, or
  2. select your requirements from the drop down boxes to build the required part

  • Reset

Found 10656 Results
Page 2 of 1776
Part No. Shell Type Plating Finish Shell Size No. of Contacts Contact Style Contacts Yes/No Polarization Size of Contacts Mating Half
D38999/26ZJ61AC Free Plug Black Zinc Nickel J=25 61 Less Pin No C 61 #20 D38999/20ZJ61BC
D38999/26ZJ61SA Free Plug Black Zinc Nickel J=25 61 Socket Yes A 61 #20 D38999/20ZJ61PA
D38999/26ZJ90BE Free Plug Black Zinc Nickel J=25 46 Less Socket No E 40 #20 , 4 #16, 2 #8 Twinax D38999/20ZJ90AE
D38999/26ZJ61AD Free Plug Black Zinc Nickel J=25 61 Less Pin No D 61 #20 D38999/20ZJ61BD
D38999/26ZJ61SB Free Plug Black Zinc Nickel J=25 61 Socket Yes B 61 #20 D38999/20ZJ61PB
D38999/26ZJ90BN Free Plug Black Zinc Nickel J=25 46 Less Socket No Normal 40 #20 , 4 #16, 2 #8 Twinax D38999/20ZJ90AN
Part No. Shell Type Plating Finish Shell Size No. of Contacts Contact Style Contacts Yes/No Polarization Size of Contacts Mating Half
Page 2 of 1776

Example Part Number


Range D38999 20 F A 35 P A
Shell Style D38999/20 Wall Mount Receptacle
D38999/24 Jam Nut Receptacle
D38999/26 RFI Self Locking Plug
Service Class and Finish F Electroless Nickel, Aluminium Alloy Shell
W Olive Drab Cadmium over Nickel, Aluminium Alloy Shell
Z Zinc Nickel, Aluminium Alloy Shell
K Stainless Steel Shell, passivated with firewall insert
S Stainless Steel Shell, electrodeposited Nickel with firewall insert
Shell Size A=9, B=11, C=13, D=15,E=17, F=19, G=21, H=23, J=25
Insert Arrangement See Insert Configurations by Shell Size Table
Contacts P Crimp Pin
S Crimp Socket
A Less Pins
B Less Sockets
Polarization N Normal
A,B,C,D (B&C not available in size 9)


D38999 Shell Style Options
D38999 III Shell Style Options

MIL-DTL-38999 Series III Insert Configurations by Shell Size

Insert Configurations by Shell Size (A1 through F32)

Shell Size - Insert Config. Service Rating Total Contacts Contact Size
22D 22M 22 20 16 12 10 8
A1 M 1 1T
A35 M 6 6
A98 I 3 3
B2 I 2 2C
B4 I 4 4
B5 I 5 5
(B13) M 13 13
B35 M 13 13
B98 I 6 6
B99 I 7 7
C4 I 4 4C
C8 I 8 8
(C22) M 22 22
C35 M 22 22
C98 I 10 10
D5 II 5 5C
D15 I 15 1 4 1C
D18 I 18 18
D19 I 19 19
D35 M 37 37
D97 I 12 8 4C
E2 M 39 38 1T
E6 I 6 6
E8 II 8 8C
E26 I 26 26
E35 M 55 55
(E55) M 55 55
E99 I 23 21 2C
F11 II 11 11C
F18 M 18 14 4T
F28 I 28 26 2C
F30 I 30 29 1C
F32 I 32 32

parenthesis ( ) : indicates inactive for new designs
C: available as coax or standard contacts, S: size 12A shielded contacts, T: Twinax contacts

MIL-DTL-38999 III LayoutsMIL-DTL-38999 Series III Insert Arrangements

Insert Configurations by Shell Size (F35 through J90)

Shell Size - Insert Config. Service Rating Total Contacts Contact Size
22D 22M 22 20 16 12 10 8
F35 M 66 66
F45 M 67 67
(F66) M 66 66
(G1) M 79 79
G11 I 11 11C
G16 II 16 16C
G24 I 24 24
G25 I 25 25
G27 1 27 27
G35 M 79 79
G39 I 39 37 2C
G41 I 41 41
G75 M 4 4T
(H1) M 100 100
H21 II 21 21C
H32 I 32 32
H34 I 34 34
H36 I 36 36
H53 I 53 53
H55 I 55 55
H97 I 16 16
H99 II 11 11
(J1) M 128 128
(J2) M 100 100
J4 I 56 48 8C
J7 M 99 97 2T
J8 M 8 8T
J11 I 11 2 9
J19 I 19 19C
J20 I 30 10 13F 4C 3T
J24 I 24 12C 12C
J29 I 29 29C
J35 M 128 128
J43 I 43 23 20C
J46 I 46 40 4 2C
J61 I 61 61
J90 I 46 40 4 2T

Contact Ratings

For information about the maximum contact rating for d38999 III connectors please see the table below:

Contact Size Test Current (A) Maximum Millivolt Drop
Crimp Solder
Standard Hermetic Standard Hermetic
22M 3 2 30 20 60
22D 5 40
22 5 3 40 20 85
20 7.5 5 35 20 60
16 13 10 25 20 85
12 23 17 25 85

Polarization Options

Shell Size Key and Keyway Arrangement Identification Angle Rotation Letter - Receptacle or Plug
A(9) N 105 140 215 265
A 102 132 248 320
B 80 118 230 312
C 35 140 205 275
D 64 155 234 304
E 91 131 197 240
B(11), C(13) and D(15) N 95 141 208 236
A 113 156 182 292
B 90 145 195 252
C 53 156 220 255
D 119 146 176 298
E 51 141 184 242
E(17), F(19), G(21), H(23) and J(25) N 80 142 196 293
A 135 170 200 310
B 49 169 200 244
C 66 140 200 257
D 62 145 180 280
E 79 153 197 272
d38999 III keying positions
D38999 III keying positions

Polarization Notes: Numbers in table are the angle of rotation in degrees (see Keying Positions diagram).

  • from main key looking clockwise onto the front face of the plug
  • from main keyway looking anticlockwise onto the front face of the receptacle

Keyway identification ‘N’ is normal.

Insert arrangements do not rotate with the main keyway.

Product Video

The video below provides an overview of the D38999 Series III connector range.

Integrated Backshell D38999 Connectors

integrated backshell d38999 iiiIntegrated backshell connectors are built to conform with the MIL-DTL-38999 series III specification so are therefore fully intermateable and interchangeable with D38999 III products. These connectors offer the performance advantages of D38999 with the following benefits over a traditional connector/backshell pairing:

  • quicker assembly;
  • space saving;
  • lower weight;
  • time-saving during ordering;
  • reduced inventory holding.

The one-piece shell construction completely integrates the straight backshell thereby enabling screen termination using either band or spring. They are manufactured in both aluminium and stainless steel with various plating options available, including Black Zinc Nickel across the 3 shell styles.

Integrated Backshell Part Number Development Table

Conesys d38999 iii integrated part number table download

Hybrid black backshell


Need accessories? These circular connectors can be ordered with a very broad range of compatible accessories, be it a simple strain relief clamp, a fully sealed RFI/EMI compatible backshell or a custom design enabling NYKCS to meet the most demanding project requirements.

NYKCS stocks a comprehensive range of circular connector backshells and protective caps (D38999-32 and D38999-33) from EMCA Electro-mechanic to suit the customers’ specific requirements. For more information contact the team or visit the relevant product page.