Aviation Connectors Explained: GX16, GX20, M12 and How to Choose the Right One

A Practical Guide for Engineers and Procurement Professionals

When building reliable industrial equipment, robotic systems, or outdoor electronic devices, the connectors you choose are just as important as the components inside. Aviation connectors — named for their original use in aircraft and military applications — are now widely used in industrial automation, medical devices, transportation, and renewable energy systems.

Among the most popular series are GX16, GX20, and M12. But what are the differences? How do you choose the right one for your application? This guide answers those questions.

Part 1: What Are Aviation Connectors?

Aviation connectors are circular, threaded locking connectors designed for harsh environments. They typically feature:

• Metal housing (zinc alloy, brass, or aluminum) for durability and EMI shielding

• Threaded coupling for vibration resistant connections

• Multiple pin configurations from 2 to 19 pins or more

• Environmental sealing options (IP67, IP68) for water and dust protection

Despite the name, these connectors are no longer limited to aviation. They are now standard in industrial controls, test equipment, medical devices, and outdoor lighting.

Part 2: GX16 Aviation Connectors

Overview

The GX16 series (also known as aviation plug type 16) is one of the most common circular connectors worldwide. The "16" refers to the thread diameter of 16mm on the coupling ring.

Key Specifications

Best Applications

• Industrial sensors – Proximity, photoelectric, and pressure sensors

• Medical equipment – Patient monitors, diagnostic devices

• Control panels – PLC connections, HMI interfaces

• Audio equipment – Microphones, stage lighting

• CCTV cameras – Outdoor surveillance power and signal

Advantages

✅ Widely available and cost effective
✅ Compact size for tight spaces
✅ Good for moderate vibration environments
✅ Easy to solder in the field

Limitations

⚠️ Not as rugged as larger series for heavy industrial use
⚠️ Standard version is not waterproof (IP68 option available)

Part 3: GX20 Aviation Connectors

Overview

The GX20 series is a larger, more heavy duty version of the GX16. The "20" indicates a 20mm thread diameter, providing more space for larger pins and higher current capacity.

Key Specifications

Best Applications

• Power supplies – High current DC power connections

• Industrial machinery – Heavy equipment, conveyor systems

• Robotics – Servo motors, robotic arm connections

• EV charging – Low voltage auxiliary connections

• Renewable energy – Solar panel interconnections

Advantages

✅ Higher current capacity (up to 20A per pin)
✅ More pin options (up to 32 pins)
✅ Larger, easier to handle in the field
✅ Better for high vibration environments

Limitations

⚠️ Larger footprint than GX16
⚠️ Higher cost
⚠️ May be oversized for small sensors

Part 4: M12 Connectors

Overview

M12 connectors are metric circular connectors with a 12mm threaded coupling. Unlike GX series, M12 is standardized under IEC 61076-2-101, making them interchangeable between manufacturers. They are the industry standard for factory automation and industrial fieldbus systems.

Key Specifications

M12 Coding Types

Best Applications

• Factory automation – Sensors, actuators, I/O modules

• Fieldbus systems – PROFIBUS, DeviceNet, CANbus

• Industrial Ethernet – PROFINET, EtherCAT, Ethernet/IP

• Robotics – End effector connections

• HVAC systems – Remote sensors and controls

Advantages

✅ International standard (interchangeable between brands)
✅ High IP rating (IP67/IP68/IP69K standard)
✅ Coding system prevents mismating
✅ Wide range of commercial off the shelf cables and connectors

Limitations

⚠️ Smaller pins limit current capacity
⚠️ More expensive than GX series
⚠️ Requires specialized tools for crimp versions

Part 5: GX16 vs GX20 vs M12 – How to Choose

Quick Comparison Table

Decision Flowchart

Step 1 – Determine current requirement

• Under 5A → GX16 or M12

• 5A to 10A → GX16 or GX20

• Over 10A → GX20

Step 2 – Determine environmental requirement

• Indoor, dry → GX16 or GX20 (IP40)

• Outdoor, wet, washdown → M12 (IP67 standard) or waterproof GX16/GX20

Step 3 – Determine signal type

• Sensor/actuator (24V) → M12 A-coded or GX16

• Ethernet (100Mbps) → M12 D-coded

• Gigabit Ethernet → M12 X-coded

• High voltage power → GX20

Step 4 – Determine need for standardization

• Need interchangeable brands → M12

• Proprietary design, cost sensitive → GX16 or GX20

Part 6: Application Examples

Example 1: Outdoor Security Camera

Requirement: 12V DC power + video signal, outdoor exposed to rain

Recommended: GX16 waterproof version (IP68) with 4 or 5 pins

• Why: Cost effective, compact, sufficient for low power, IP68 provides rain protection

Example 2: Factory Automation Sensor Network

Requirement: 24V power and signal for 50 proximity sensors on a production line

Recommended: M12 A-coded with 4 or 5 pins

• Why: Standardized, IP67 rated for factory floor, widely available, coded to prevent errors

Example 3: Industrial Robot Servo Motor

Requirement: 480V 20A three phase power + brake + encoder signals

Recommended: GX20 with 12 to 19 pins, high current version

• Why: Higher current capacity, multiple pins for mixed signals, rugged threaded lock for vibration

Example 4: Portable Medical Device

Requirement: Battery charging and data logging connection, frequent mating cycles

Recommended: GX16 with 6 pins (nickel plated for wear resistance)

• Why: Lower cost, compact, good cycle life, easy to solder for low volume production

Part 7: Why Choose Fengy Automation for Aviation Connectors

At Shanghai Fengy Cable Technology Co., Ltd. we manufacture and supply high quality aviation connectors and pre assembled cable harnesses for global customers.

Our capabilities include:

• ✅ GX16, GX20, and M12 series in stock

• ✅ 2 to 32 pins configurations

• ✅ IP40 to IP68 protection ratings

• ✅ PVC, rubber, silicone, and LSZH cable options

• ✅ Custom lengths from 0.3m to 20m

• ✅ Full harness assembly – stripped ends, pre terminated, overmolded

• ✅ CE, RoHS, ISO 9001 certified

• ✅ Low MOQ from 200 pieces

• ✅ Sample in 7 days – Bulk in 15 to 20 days

• ✅ Exported to 50+ countries

Whether you need standard off the shelf connectors or fully customized cable assemblies, we have the engineering expertise and production capacity to deliver.

Contact Shanghai Fengy Cable Technology Co., Ltd.

📧 Email: [sales@fengytec.com]
🌐 Website: [www.fengytec.com ]
📞 Tel/WhatsApp: [+86 18049718222]

Your trusted partner for aviation connectors and custom cable assemblies.