38999-type circular connectors · Updated 2026-10-28
D38999 to J599 Part Number Cross-Reference
You have a D38999 part number on a drawing or a bill of materials and need the J599 configuration to quote. J599 Series III is our 38999 Series III-type connector, built to GJB 599B Series III, the Chinese counterpart of MIL-DTL-38999 Series III. Its part numbers use the same segments as D38999 Series III part numbers, so most numbers can be read across field by field.
Send us your D38999 part number; we will propose the matching J599 configuration and provide samples for your own mating test.
The two numbers side by side
| Field | D38999/26WB35SN | J599/26WB35SN | What it means in J599 |
|---|---|---|---|
| Prefix | D38999/ | J599/ | Series III-type connector |
| Type | 26 | 26 | Plug |
| Finish | W | W | Aluminum alloy, olive-drab cadmium |
| Shell | B | B | Shell size 11 |
| Insert arrangement | 35 | 35 | Arrangement 11-35: 13 × size 22D |
| Contact | S | S | Crimp socket contacts |
| Key | N | N | Normal key position |
Each segment is checked against the J599 Series III ordering code below. For decoding the number itself, see how to read a 38999 part number.
Field 1: slash type
| D38999 slash number | J599 type | Connector |
|---|---|---|
| D38999/20 | J599/20 | Square-flange receptacle, crimp contacts |
| D38999/24 | J599/24 | Jam-nut receptacle, crimp contacts |
| D38999/26 | J599/26 | Plug, crimp contacts |
| D38999/21, /23, /25, /27 | J599/21, /23, /25, /27 | Hermetic receptacle: square flange, jam nut, solder mount, weld mount |
J599 also offers hermetic feed-through (bulkhead) receptacles, coded J599/20…C and J599/24…C, which mate with a standard plug on one side and a -U reverse-side plug on the other. If your slash number is not in the table, send us the part number and we will review it.
Field 2: finish letter
The finish letter sets shell material and plating. We read the letter in your D38999 number against the J599 finish table:
| Letter | Shell material | Finish | Salt spray | Temperature |
|---|---|---|---|---|
| F | Aluminum alloy | Nickel | 48 h | −65 to +200 °C |
| W | Aluminum alloy | Olive-drab cadmium | 500 h | −65 to +175 °C |
| T | Aluminum alloy | Nickel-PTFE | 500 h | −65 to +175 °C |
| K | Stainless steel | Passivated | 500 h | −65 to +200 °C |
| S | Stainless steel | Nickel | 48 h | −65 to +200 °C |
| M | Composite | Nickel | 2000 h | −65 to +200 °C |
| J | Composite | Olive-drab cadmium | 2000 h | −65 to +175 °C |
| Y | Stainless steel (hermetic) | Electropolished | 500 h | −65 to +200 °C |
| TA | Titanium alloy | None | 500 h | −65 to +200 °C |
Put the shell material and plating from your drawing in the inquiry next to the part number, and we confirm the finish with the quotation. Cadmium finishes (W, J) are not RoHS compliant and are supplied on request; for EU shipments, choose a nickel or composite finish. For more on finishes, see shell finishes and salt spray.
J599 adds one option that sits between the type and the finish: class MT, a 260 °C high-temperature version in stainless steel only.
Field 3: shell letter
| Letter | A | B | C | D | E | F | G | H | J |
|---|---|---|---|---|---|---|---|---|---|
| Shell size | 9 | 11 | 13 | 15 | 17 | 19 | 21 | 23 | 25 |
Field 4: insert arrangement
The digits after the shell letter give the layout within that shell. J599 Series III has 184 insert arrangements, for example 11-35 (13 × size 22D), 25-35 (128 × size 22D) and 25-61 (61 × size 20). Contact counts, sizes and service ratings for every layout are on the J599 Series III page; service ratings are explained in 38999 insert arrangements and service ratings.
Field 5: contact letter
| Letter | J599 meaning |
|---|---|
| P / S | Pin / socket, crimp |
| H / J | Pin / socket, 1500 mating cycles (composite shells) |
| P | Solder-sealed pin (hermetic receptacles) |
| C | Feed-through pin (hermetic feed-through receptacles) |
Crimp contacts carry from 2 A (size 26) to 33 A (size 10).
Field 6: key position
N is the normal key position; A, B, C, D and E are alternate positions. Six key positions let several connectors of the same size and layout sit on one panel without cross-mating.
Suffixes
J599 suffixes are -U (reverse-side plug), V (fluorosilicone, oil-resistant seals; not with MT) and R(X) (NiCr–NiSi thermocouple contacts, X = number of pairs). If your number ends in a suffix that is not on this list, send it to us as written.
Worked examples
1. D38999/26WB35SN → J599/26WB35SN Plug, aluminum alloy with olive-drab cadmium, shell 11, arrangement 11-35 (13 × size 22D, 5 A per contact), crimp sockets, normal key.
2. D38999/20FJ61PN → J599/20FJ61PN Square-flange receptacle, aluminum alloy with nickel (48 h salt spray, −65 to +200 °C), shell 25, arrangement 25-61 (61 × size 20, 7.5 A per contact), crimp pins, normal key.
3. D38999/24KE26PA → J599/24KE26PA Jam-nut receptacle, passivated stainless steel (500 h salt spray), shell 17, arrangement 17-26 (26 × size 20), crimp pins, alternate key A.
For hermetic types (/21, /23, /25, /27), the J599 number uses a hermetic stainless steel shell (Y electropolished or N nickel) or a titanium (TA) shell and P solder-sealed pins. J599 hermetic receptacles have a leak rate of ≤ 1 × 10⁻⁸ Pa·m³/s at 0.1 MPa pressure differential; see hermetic connector leak rates explained.
Series I, II and IV numbers
Our other 38999-type series are numbered differently from J599 Series III, so they do not read across field by field:
- GJB599 Series I (bayonet, built to GJB 599A Series I): JY + type + class + shell number + finish, for example JY27505E15F35SN.
- GJB599 Series II (low-profile bayonet, shells 8 to 24): the same JY structure, for example JY27508E14F35SN.
- GJB599 Series IV (quarter-turn, built to GJB 599A Series IV): J599/40 to /49 type codes with shell letters B to J, for example J599/40FB35PN.
For a D38999 Series I, II or IV number, send us the part number; we will propose the matching configuration and provide samples for your mating test. The differences between the four series are covered in 38999 Series I, II, III and IV.
Protective caps
J599 Series III caps are ordered separately as J599/32 (plug cap) or J599/33 (receptacle cap) + finish + shell size + lanyard, for example J599/32F09R. Note that the cap number uses the shell size (09 to 25), not the shell letter. Send us the connector part numbers and we will list the matching protective caps.
What to send us
- The complete D38999 part number for each connector, including any suffix.
- Quantity, and whether you need RoHS compliance.
- The drawing or datasheet page, if you have it.
We propose the J599 configuration with the quotation. Samples are built to order in 4–8 weeks for your own mating test, with third-party testing on request; production lead time is 4–8 weeks and the minimum order is 10 pieces. Request a quote with your part numbers.
