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Complete guide to M8 connectors. Learn about field wireable, molded cable, and panel mount types. Pinout configurations from 3-pin to 8-pin. IEC 61076-2-104 compliant.

An M8 connector is a compact circular industrial connector with an 8mm thread outer diameter. It follows the IEC 61076-2-104 standard and is widely used in factory automation, process control, and compact sensor applications. The threaded coupling provides reliable vibration resistance in demanding environments.

Key specifications shared across KRONZ M8 connector families:

• Standard: IEC 61076-2-104
• Protection rating: IP67
• Insulation resistance: ≥100MΩ
• Contact resistance: ≤5mΩ
• Operating temperature: -25°C to +85°C
• Mechanical life: >100 mating cycles
• Pollution degree: 3
• Nut material: Alloy, copper-zinc, nickel-plated
• Contact material: Copper alloy, gold-plated
• Sealing material: FPM/FKM

The 8mm thread makes M8 connectors the standard choice for space-constrained sensor and actuator wiring. They handle signal and power transmission in significantly less panel space than M12.

Need to compare M8 with M12? See our detailed M12 vs M8 Connector comparison.

Starting a new project? Our M12 Connector Selection Guide covers the full connector selection framework.

Compact machinery and miniaturized sensors demand compact connectors. M8 fills the gap where M12 is too large but a bare wire or smaller connector would not provide sufficient protection or reliability.

Wrong connector size choices lead to mechanical fit failures, insufficient pin count for complex signals, or unnecessary cost from overspecification. M8 handles three-wire sensor signals, four-wire sensor configurations, and six-pin dual-channel setups without the spatial footprint of larger connectors.

Field workers benefit from M8's IP67 sealing in compact enclosures where water and dust protection remain essential. The standardized IEC 61076-2-104 interface ensures interoperability across equipment from different manufacturers.

M8 connectors appear across industries wherever sensors and small actuators need reliable, sealed connections. Automotive manufacturing uses M8 connectors in door modules and seat control units. Packaging machinery relies on them for photoelectric sensors on high-speed filling lines. Food and beverage processing applies M8 connectors in washdown zones where compact IP67 sealing is required alongside frequent sanitation cycles. Medical device assembly uses M8 connections for diagnostic equipment where signal integrity in tight enclosures is critical.

KRONZ offers three main M8 connector categories: field wireable, molded cable, and panel mount (flange). Each serves different installation scenarios.

Field wireable M8 connectors allow on-site wiring with screw terminal connections. They are available in straight and 90° angled housings.

Straight Type (H080xM/F):

• H0803M/H0803F: 3-pin, A-CODE, 3A at 60V
• H0804M/H0804F: 4-pin, A-CODE, 3A at 60V
• H0805BM/H0805BF: 5-pin, B-CODE, 3A at 30V

Angled Type (H080xMA/FA):

• H0803MA/H0803FA: 3-pin, A-CODE, 3A at 60V
• H0804MA/H0804FA: 4-pin, A-CODE, 3A at 60V
• H0805BMA/H0805BMA: 5-pin, B-CODE, 3A at 30V

Cable outlet diameter: 3.5-5mm across all models. Screw connection method supports fast, tool-accessible field termination.

Typical applications include compact proximity sensors, photoelectric sensors, and pneumatic valves in tight mounting locations.

M8 Molded Cable Connectors

Pre-molded M8 connectors ship with factory-terminated cables in PVC or PUR jacket. Standard lengths are 2m, 5m, and 10m, with custom lengths available.

Female Straight Molded (M080xF):

Wire color codes follow IEC standards: BN (brown) = Pin 1, WH (white) = Pin 2, BU (blue) = Pin 3, BK (black) = Pin 4, GY (gray) = Pin 5, PK (pink) = Pin 6.

Male Straight Molded (M080xM):

Same pin configurations as female versions, rated for the same current and voltage. Male connectors mate with female field wireable or panel mount counterparts.

Typical applications include pre-wired sensor assemblies, compact actuator connections, and OEM equipment where consistent cable lengths simplify installation.

M8 flange connectors provide secure board mounting with rear-fastened or front-fastened options. They support solder cup and PCB termination types. The flange design distributes mounting stress across a wider area, reducing the risk of cracking in thin-walled enclosures or PCB assemblies.

Rear Fastened (F080xF-SR/M8C, F080xF-PR/M8C):

Front Fastened (F080xF-SF/M8C, F080xF-PF/M8C):

Front-fastened models secure from the panel front, simplifying assembly in pre-drilled enclosures. The nut fastens from the component side, eliminating the need to access the rear of the panel during installation. Available in solder cup and PCB termination variants for 3-pin through 8-pin configurations.

Male Panel Mount (F080xM-SR/M8C, F080xM-PR/M8C):

Male flange connectors provide the panel interface for male-side connections. Both rear-fastened and front-fastened options cover 3-pin to 8-pin configurations. Male panel mount connectors mate with field wireable female connectors or molded cable connectors mounted elsewhere in the system.

Panel mount connectors suit PCB-level integrations, compact control cabinets, and equipment where connectors must be permanently mounted to enclosure panels. The solder cup versions accept individual wire leads for custom wiring, while PCB versions drop directly onto a board for automated assembly.

M8 connectors support pin counts from 3 to 8, serving both sensor and industrial bus applications.

3-Pin (A-CODE): Two-wire DC sensor standard. Pin 1 carries power (+), Pin 3 carries power (-), with Pin 4 serving as signal ground shared with the power return. Suitable for basic on/off sensors.

4-Pin (A-CODE): Three-wire DC sensor configuration. Dedicated power (+), power (-), and independent signal line. Eliminates shared ground loops for cleaner signal transmission in analog and digital sensors.

5-Pin (B-CODE): Industrial bus standard, commonly used for sensor networks. Five pins support differential signal pairs plus auxiliary functions.

6-Pin (A-CODE): Dual-channel sensor or sensor-plus-auxiliary configuration. Two independent signal paths in a single connector reduce panel space and wiring complexity.

8-Pin (A-CODE): Highest density M8 configuration. Eight pins accommodate multiple signal channels, auxiliary contacts, or combined power and data in a single compact interface.

Coding assignment depends on the application:

• A-CODE: Sensor and actuator connections (3 to 8 pins)
• B-CODE: Industrial bus and device-level networks (5 pins)

M8 vs M12: Key Differences

M12 dominates general factory automation and Ethernet networking. M8 serves compact sensor applications where panel space is limited. The two connector families are mechanically incompatible due to the different thread sizes.

Selection Guide

Choosing the right M8 connector requires matching the application requirements to the available configurations.

Step 1: Determine the pin count

Start with the signal and power requirements. A simple two-wire sensor needs 3 pins. Independent signal and power require 4 pins. Dual-channel sensors or bus networks may need 5, 6, or 8 pins.

Step 2: Select the coding

Use A-CODE for sensor and actuator power and signal applications. Choose B-CODE when the connection serves industrial bus or network functions.

Step 3: Choose the assembly type

Field wireable connectors suit on-site installation, modifications, and maintenance scenarios where cable lengths are not known in advance. Molded cable connectors provide consistent quality for fixed-length pre-wired sensor assemblies. Panel mount connectors are the right choice when the connector must be mounted to a panel, enclosure, or PCB.

Step 4: Match electrical ratings

Check the connector's current and voltage ratings against circuit requirements. A-CODE 3-pin and 4-pin models deliver 3A at 60V. Higher pin counts and B-CODE configurations have lower current ratings. Higher pin count ratings often catch people off guard.

Full connector selection framework: M12 Connector Selection Guide
Pinout details: M12 Connector Pinout Guide

Mismatching thread size: M8 and M12 are not interchangeable. Always verify the thread diameter specified in the equipment drawing before ordering.

Ignoring coding differences: A-CODE and B-CODE M8 connectors look similar but serve different purposes. Using the wrong coding can result in signal incompatibility or failed device communication.

Overlooking current derating: Higher pin count M8 connectors (6-pin and 8-pin) have lower current ratings than 3-pin and 4-pin versions. A 1.5A 8-pin connector cannot carry the same current as a 3A 4-pin connector.

Skipping IP rating verification: All KRONZ M8 connectors are rated IP67, but cable jacket material affects environmental performance. PVC jackets suit general-purpose indoor applications. PUR jackets offer better resistance to oil, abrasion, and outdoor exposure.

Forgetting cable orientation: Male and female connectors must be specified correctly. Mixing up the orientation in the ordering code means the connector will not mate with the intended counterpart.

Using M8 for Ethernet: M8 connectors do not support D-CODE or X-CODE Ethernet configurations. Industrial Ethernet protocols such as PROFINET and EtherNet/IP rely on the larger M12 form factor for signal integrity at data rates up to 1Gbps and beyond. M8 can handle digital I/O and sensor signals but not high-speed data networking. Attempting to run Ethernet over M8 connections typically results in intermittent communication failures and increased bit error rates.

M8 connectors serve compact sensor and actuator wiring across factory automation, process control, and compact machinery. IEC 61076-2-104 standardization, IP67 protection, and pin configurations from 3 to 8 contacts cover the full range of space-constrained applications.

Field wireable, molded cable, and panel mount types handle every installation scenario, from on-site wiring to OEM pre-assembly to PCB integration. Specifying the correct pin count, coding, and assembly type at the design stage avoids field issues and reduces installation cost.

M8 adoption continues to grow in automotive, packaging, and food processing as machinery miniaturizes. Getting the connector specification right early is far cheaper than fixing it during installation.

KRONZ provides M8 connector solutions across the full product range. Contact us for technical support, custom configurations, or volume pricing.

Available services:

• Technical consultation for connector selection
• Custom cable assemblies and connector configurations
• Sample requests for prototyping and testing
• Volume pricing for production orders

Contact KRONZ to discuss your M8 connector requirements.

Related Articles

• M12 Connector Selection Guide — Full connector selection framework for industrial automation
• M12 vs M8 Connector — Side-by-side comparison of M12 and M8 specifications
• M12 Connector Pinout Guide — Detailed pinout configurations and wiring diagrams
• M12 Connector IP Rating Guide — Environmental protection ratings explained
• M12 Connector Applications — Industry use cases for industrial circular connectors
• M12 Connector Current Rating Guide — Current and voltage specifications across pin configurations