Four‑position colour‑marked gold‑plated replaceable contacts for stable power‑signal transmission
Matte‑black square flange alloy housing, easy and firm panel installation
Triple‑start thread locking design, excellent anti‑loose property under heavy vibration
High‑temperature‑resistant green insulator with A‑D letter marks for error‑free wiring
Complete accessory set including gasket, dust cap, insertion tool and spare‑pin container
Wide‑range working temperature ‑55℃~+175℃, adaptable to harsh industrial environments
EMI‑shielded metal shell, reliable dust‑proof and water‑splash‑resistant sealing performance
Product pictures
D38999/20WD04PN four‑core flange‑fixed circular socket connector adopts letter‑marked green insulator, detachable gold‑plated pins, sealing gasket and full‑set mounting accessories. The vibration‑resistant threaded‑lock housing provides reliable power and signal transmission for industrial and civilian‑grade electronic equipment.
These pictures exhibit the full assembly of D38999/20WD04PN 4‑position flange‑mount circular socket connector. The square four‑hole metal flange shell supports panel installation. The built‑in green high‑temperature‑resistant insulator is printed with A‑D alphabet labels for four contact holes.
The complete package includes colour‑ring marked gold‑plated separable contact pins, black rubber sealing gasket, plastic terminal‑assembly tool, dust‑proof protective cap and transparent storage bottle for spare pins. All spare contacts are independent and replaceable for convenient on‑site wiring and maintenance.


Product description
D38999/20WD04PN is a 4‑pin flange‑mount receptacle‑type circular connector from the classic D38999 industrial connector series. It comes with full‑range matching spare parts for assembly and maintenance.
This connector adopts triple‑start threaded‑locking alloy housing and rubber sealing washer to deliver great shock‑resistance, dust‑proof and splash‑proof performance in harsh working environments. Removable gold‑plated copper contacts feature low contact resistance, excellent electrical conductivity and long‑term anti‑oxidation property. The alphabet‑coded insulator prevents wiring mistakes. Rich accessories including installation tool, dust cap and spare‑pin container simplify terminal replacement and daily equipment upkeep.
It is widely used on new‑energy power units, rail‑transit control components, automated machinery, testing instruments and civilian electronic facilities for stable power‑signal connection.


Workshop
We run a full‑chain manufacturing plant dedicated to all kinds of industrial connector goods. Every single component you see on our finished items gets crafted right on‑site by our own workshop crews.
Our in‑house workshops handle CNC turning for metal connector shells. We’ve got a small, skilled mould‑making team that works on custom tooling design. A big collection of finished mould templates is stored onsite, which helps us churn out insulating parts and silicone rubber accessories. All the core mechanical pieces‑‑contact springs, mating ports and anti‑interference shield springs‑‑are produced locally within our factory space.
We built dedicated working stations to stamp and shape our metal contact terminals. Every terminal piece is made to satisfy the requirements laid down in the international M39029 industry standard. When our factory first got off the ground, most of our manufactured parts went to supply the AVIC Group.
Our long‑time assembly workers carry out careful inspections during every production stage. They make certain every finished‑off connector meets the strict criteria of the MIL‑DTL‑38999 military‑grade specification.



Exhibition
Great client service is something our team always prioritizes. We aim to deliver a pleasant buying journey for every overseas partner. We make regular trips to major electronics trade fairs around the industry. These in‑person meet‑ups make it simple for us to chat with buyers, gather real‑world usage feedback and work out ways to refine our goods. Face‑to‑face conversations like these allow us to build dependable, long‑lasting business partnerships with clients all over the world.


Package
Wondering how we pack connectors before shipment? Let me walk you through our real packing routine step by step.
First off, every unit gets wrapped with soft tough anti-scratch foam right before leaving our workshop. Rough highway and sea shipping always bring bumps and friction, and this foam keeps metal shells free of ugly scratches that often come from poor packaging.
After foam wrapping, we place each connector into a separate ESD sealed box. These internal pins and inserts are extremely delicate; static electricity can burn out tiny parts without visible signs. This sealed box blocks static risk entirely, and it’s one of our most important protective steps.
Our packing team will double-check every finished package manually. Only confirmed good items go into reinforced dedicated cartons. We print part number, batch count and total quantity clearly on carton surfaces, so your warehouse team can sort and stock goods quickly once delivery arrives.
You can pick international express, air freight or sea shipping freely. Our logistics team adjusts arrangements fully to match your preferred delivery method.
All outer cartons go through extra reinforcement work. They resist compression and shock far better than ordinary generic cartons.
Long cross-border shipments always have shaking and squeezing on the way. Our layered packing design absorbs most impact, cuts transit damage greatly, and makes sure every single connector lands intact at your site.


| Contact Material | High‑purity copper, gold‑plated detachable contacts with colour‑code rings |
| Shell Material | 6061‑T6 aluminium alloy, matte‑black anodized finish |
| Insulator Material | High‑temperature‑resistant green engineering plastic |
| Lock‑up Mode | Triple‑start threaded screw locking |
| Mounting Type | Square 4‑hole flange panel mounting |
| Main Application | New‑energy equipment, rail‑transit components, industrial automation, precision test instruments |
Why choose us?
1. With its own molds, it can achieve large-scale production. The molds have been repeatedly finely engraved, ensuring the insulation structure and quality from the very beginning!
2. We have professional shell processing manufacturers. The shell materials and structures are completely consistent with Amphonel and fully comply with the MIL-DTL-38999 standard.
3. We have our own contact component production line. The quality of the contact components fully meets the M39029 standard!
4. Our workers have undergone strict training and produce according to the production process of standard connectors strictly.
5. After all products are assembled, each product will undergo individual quality inspection and then be packaged and shipped.
FAQ:
1. who are we?
We are based in Henan, China, start from 2025,sell to Mid East(50.00%),Domestic Market(30.00%),Southeast Asia(20.00%). There are total about 51-100 people in our office.
2. how can we guarantee quality?
Always a pre-production sample before mass production;
Always final Inspection before shipment;
3.what can you buy from us?
MIL-DTL-38999 Series connectors,militray connectors,Aorespace connectors,MS27484 series connector,Arinc 600 Series connectors
4. why should you buy from us not from other suppliers?
Our engineering team is come from AVIC, and we have a specialized R & D team for product development. With a wealth of ready - made molds, we can ensure large - scale production. To guarantee product quality, we have inspection equipment and a laboratory.
5. what services can we provide?
Accepted Delivery Terms: FOB,CIF,EXW,Express Delivery;
Accepted Payment Currency:null;
Accepted Payment Type: T/T,L/C,D/P D/A;
Language Spoken:English