MX4.2mm Wire-to-Board Connectors – Compatible with Molex Mini-Fit
MX4.2mm Wire-to-Board Connectors – Compatible with Molex Mini-Fit Jr. Series
Yoeruyo's MX4.2mm connector range provides reliable wire-to-board and wire-to-wire interconnection solutions at the 4.2mm pitch, fully compatible with the Molex Mini-Fit Jr. series — one of the most widely deployed power connector systems in PC power supplies, server infrastructure, industrial equipment, and automotive electronics. Our range includes dual-row housings, PCB receptacle headers, and crimp terminals in a comprehensive pin count selection.
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Pitch | 4.2mm |
| Circuit Count | 2 to 24 circuits (dual row: 1×2 to 6×4) |
| Wire Range | 0.5mm² – 2.5mm² (AWG 20–14) |
| Rated Voltage | 600V AC/DC (UL rating) |
| Rated Current | 13A per contact (AWG 18); 9A (AWG 20) |
| Contact Material | Copper alloy, tin plated |
| Housing Material | PA66 (Nylon 66), UL94 V-0, natural or black |
| Operating Temperature | -40°C to +105°C |
| Locking | Dual-beam positive latch with secondary lock option |
| Mating Cycles | ≥30 cycles |
| Compliance | RoHS, REACH; UL-recognized |
Product Components
- Wire-side housing (plug) – dual-row receptacle housing accepting MX4.2mm crimp terminals; 2 to 24 circuits
- PCB header (right-angle & vertical) – through-hole PCB-mount receptacle for wave or hand soldering; vertical and right-angle orientations
- Crimp terminals (female) – stamped and formed copper alloy terminals for crimping onto AWG 14–20 wire
- Panel-mount headers – flange-mount PCB headers for chassis and panel integration
- Pre-crimped wire assemblies – custom wire-to-connector assemblies available for OEM integration
Application Scenarios
- PC & server power supplies – ATX main power, CPU auxiliary (4-pin/8-pin EPS), and peripheral power connectors in desktop and server PSUs
- Industrial power distribution – power input and output connections in industrial control panels, motor drives, and UPS systems
- Automotive electronics – ECU power connections, body control module wiring, and high-current automotive wire harness assemblies
- Telecommunications equipment – power distribution in rack-mount telecom and networking equipment
- LED drivers & lighting systems – power input connections in commercial LED driver modules and lighting control systems
- Robotics & automation – servo drive power connections, motor controller wiring, and power distribution in robotic systems
Why Choose Yoeruyo MX4.2mm Connectors
- ✅ Molex Mini-Fit Jr. compatible – dimensionally and electrically compatible with Molex 39-01 series housings and 39-00 series terminals
- ✅ High current rating – up to 13A per contact for reliable power distribution in demanding applications
- ✅ Dual-beam positive latch – audible click confirmation and secure retention prevent accidental disconnection under vibration
- ✅ UL-recognized – 600V AC/DC UL rating for use in safety-critical power applications
- ✅ Bulk & OEM supply – flexible MOQ and tiered pricing for PSU manufacturers, system integrators, and wire harness assemblers
Buying Guide – Selecting the Right MX4.2mm Component
- Circuit count – select the number of circuits to match your power distribution requirements; dual-row housings are available from 2 to 24 circuits
- Wire gauge – match the crimp terminal to your wire cross-section; AWG 18 (0.75mm²) is the most common for 10A–13A circuits
- PCB header orientation – vertical headers for standard board-to-wire connections; right-angle for edge-mount and space-constrained PCB layouts
- Secondary lock – recommended for vibration-prone and safety-critical applications to prevent terminal back-out
- Pre-crimped assemblies – for OEM integration, pre-crimped wire assemblies eliminate the need for crimping tools and reduce assembly time
Frequently Asked Questions
Are these connectors compatible with Molex Mini-Fit Jr.?
Yes. Yoeruyo MX4.2mm housings and terminals are dimensionally compatible with Molex Mini-Fit Jr. (39-01 series housings, 39-00 series terminals). They mate correctly with genuine Molex Mini-Fit Jr. counterparts.
What is the maximum current rating per contact?
The MX4.2mm terminal is rated at 13A per contact with AWG 18 wire, and 9A with AWG 20 wire. For multi-circuit power applications, ensure the total current load is distributed appropriately across circuits.
Can I use these in ATX PC power supply applications?
Yes. The MX4.2mm (Mini-Fit Jr. compatible) connector is the standard used for ATX 24-pin main power, 4-pin/8-pin EPS CPU power, and 6-pin/8-pin PCIe power connectors in PC power supplies.
Do you offer pre-crimped wire assemblies?
Yes. Custom wire-to-connector assemblies with pre-crimped MX4.2mm terminals are available in specified wire lengths, gauges, and circuit counts. Contact us for OEM assembly quotations.
What crimping tool is required?
MX4.2mm terminals require a dedicated crimp tool compatible with Molex Mini-Fit Jr. terminals (e.g., Molex 63819-0900 or equivalent). A proper ratchet crimp tool is essential for reliable, low-resistance crimps in production environments.
