Molex Connector Types: A Complete Guide to Series, Specs & Applications
Molex is one of the world's largest connector manufacturers, with hundreds of connector series used across automotive, industrial, consumer electronics, and PC hardware. This guide covers the most common Molex connector types, their key specs, and real-world applications — including how they compare to JST connectors.
Most Common Molex Connector Types Overview
| Series | Pitch | Current | AWG | Primary Application |
|---|---|---|---|---|
| PicoBlade | 1.25mm | 1A | 28–32 | Drones, wearables, IoT |
| Micro-Latch | 2.0mm | 2A | 24–30 | Consumer electronics, automotive |
| KK 254 | 2.54mm | 3A | 22–28 | PC fans, Arduino, breadboards |
| SL | 2.54mm | 3A | 22–26 | PC disk drives, legacy peripherals |
| Micro-Fit 3.0 | 3.0mm | 5A | 18–24 | Servers, industrial power |
| Mini-Fit Jr. | 4.2mm | 9A | 16–22 | ATX power supply, PC motherboard |
1. Molex KK 254 — 2.54mm Pitch
The most widely used Molex series in PC and hobbyist electronics. The 2.54mm pitch matches standard DuPont/breadboard spacing, making it extremely versatile.
- Pitch: 2.54mm
- Current: 3A per contact
- Wire AWG: 22–28
- Mount: Through-hole
- Locking: Positive latch
Best for: PC fan connectors, internal PC wiring, Arduino shields, breadboard connections.
Shop Molex KK 254 2.54mm Connectors →
2. Molex Micro-Fit 3.0 — 3.0mm Pitch
A high-current connector designed for power distribution in servers, workstations, and industrial equipment. Features a dual positive latch for secure connections under vibration.
- Pitch: 3.0mm
- Current: 5A per contact
- Wire AWG: 18–24
- Mount: Through-hole / panel mount
- Locking: Dual positive latch
Best for: Server power supplies, industrial power distribution, automotive wiring harnesses.
Shop Molex Micro-Fit 3.0mm Connectors →
3. Molex Mini-Fit Jr. — 4.2mm Pitch
The standard connector for ATX PC power supplies — the 24-pin main connector and 4/8-pin CPU connector on virtually every desktop motherboard are Mini-Fit Jr. It supports up to 9A per contact, making it one of the highest-rated common connectors.
- Pitch: 4.2mm
- Current: 9A per contact
- Wire AWG: 16–22
- Mount: Through-hole
- Locking: Positive latch
Best for: ATX power supplies, PC motherboard power connectors, high-current industrial applications.
Shop Molex Mini-Fit Jr. 4.2mm Connectors →
4. Molex PicoBlade — 1.25mm Pitch
Molex's ultra-compact connector series, directly competing with JST GH (1.25mm). Popular in drones, wearables, and compact electronics. Note: PicoBlade and JST GH share the same pitch but are NOT interchangeable.
- Pitch: 1.25mm
- Current: 1A per contact
- Wire AWG: 28–32
- Mount: SMD / Through-hole
- Locking: Friction lock
Best for: FPV drones, wearables, compact IoT devices, GPS modules.
Shop Molex PicoBlade 1.25mm Connectors →
5. Molex Micro-Latch — 2.0mm Pitch
A compact connector series comparable to JST PH (2.0mm), used in consumer electronics and automotive applications. Not interchangeable with JST PH despite the same pitch.
- Pitch: 2.0mm
- Current: 2A per contact
- Wire AWG: 24–30
- Mount: Through-hole
- Locking: Positive latch
Best for: Consumer electronics, automotive sensors, small appliances.
Shop Molex Micro-Latch 2.0mm Connectors →
6. Molex SL — 2.54mm Pitch
A single-row connector series widely used in PC internal wiring, particularly for disk drives and legacy peripherals. Shares the 2.54mm pitch with KK 254 but has a different housing profile.
- Pitch: 2.54mm
- Current: 3A per contact
- Wire AWG: 22–26
- Mount: Through-hole
- Locking: Friction lock
Best for: PC disk drive connectors, legacy peripheral wiring, industrial control panels.
Molex vs JST: Key Differences
| Feature | Molex | JST |
|---|---|---|
| Origin | USA | Japan |
| Pitch range | 1.25mm–4.2mm (common) | 1.0mm–3.96mm (common) |
| Current range | 1A–9A+ | 1A–10A |
| Primary market | PC, automotive, industrial | Consumer electronics, drones, hobbyist |
| Availability | Wide (global distributors) | Wide (especially Asia) |
| Clone ecosystem | Limited | Extensive |
Quick Selection Guide
| Application | Recommended Connector |
|---|---|
| PC fan / internal wiring | Molex KK 254 (2.54mm) |
| ATX power supply | Molex Mini-Fit Jr. (4.2mm) |
| Server / industrial power | Molex Micro-Fit 3.0 (3.0mm) |
| FPV drone / compact IoT | Molex PicoBlade (1.25mm) |
| Consumer electronics | Molex Micro-Latch (2.0mm) |
| Legacy PC peripherals | Molex SL (2.54mm) |
Common Mistakes to Avoid
- Confusing KK 254 with DuPont: Both use 2.54mm pitch but have different housing shapes and are not interchangeable
- Exceeding current rating: Mini-Fit Jr. supports 9A per contact — always verify before use
- Mixing Molex and JST: PicoBlade (1.25mm) and JST GH (1.25mm) share the same pitch but are NOT compatible
- Using wrong AWG: Each series has a rated wire gauge range — out-of-spec wire damages contacts
Related Guides
- 📌 JST Connector Types: Complete Guide to SH, GH, PH, XH, VH & More
- 📌 How to Identify JST Connectors: Pitch, Series & Pin Count Guide
- 📌 JST XH Connector: Complete Guide & FAQ
- 📌 JST VH Connector: Complete Guide to Types, Pinout & Specs
Frequently Asked Questions
What is the most common Molex connector?
The Molex Mini-Fit Jr. (4.2mm) is the most recognized — it's the standard ATX power connector used in virtually every desktop PC. For signal-level connections, the KK 254 (2.54mm) is the most widely used.
Are Molex and JST connectors interchangeable?
No. Even when pitch matches (e.g. PicoBlade and JST GH are both 1.25mm), the housing shapes and locking mechanisms are different. They cannot be mated.
Where can I buy Molex-compatible connectors?
Browse our connector collection for JST and Molex-compatible options, including KK 254, PicoBlade, Micro-Fit 3.0, and Mini-Fit Jr. Ships worldwide with no minimum order quantity.