Skip to main content
Contact Us
RUGGED COMPUTING · CONNECTORS

What Is the Difference Between M8 and M12 Connectors?

M8 and M12 are circular industrial connectors named after their thread size: 8 mm and 12 mm. M8 is smaller, with 3 to 8 pins, and suits compact sensors and low-power signals. M12 is larger, with up to 12 pins and more coding options, and carries higher power and Ethernet, which is why industrial computers use it.

01

The Short Answer

Both connectors screw together and seal to IP67 or better when mated. The difference is size and capacity: M8 saves space on small sensors, while M12 has room for more pins, higher currents and the twisted pairs Ethernet needs.

  • //
    Thread M8: 8 mm. M12: 12 mm.
  • //
    Pins M8: 3, 4, 6 or 8. M12: 3 to 12.
  • //
    Power M8 is for low currents; M12 has dedicated power codings.
  • //
    Ethernet M8 is used for some compact 100 Mbps links; M12 D and X coding cover 100 Mbps to 10 Gbit/s.
  • //
    Typical use M8: small sensors. M12: sensors, actuators, Ethernet, power and computers.
02

Which to Use

Use M8 where space on a sensor or small actuator is the constraint. Use M12 for everything that carries real power or network data, including the I/O on rugged and waterproof computers. Our guide to M12 connectors covers coding, pinouts and sizes.