Micro-Bayonet | Rugged Micro Bayonet Circular Connector

Micro bayonet circular connector solutions like the Micro-Bayonet Connector Series give designers a compact, lightweight way to route low power and signal lines in harsh industrial environments without the cost of full mil-spec circulars. With a rugged metal shell, triple bayonet coupling, and high-density size 22D contacts, Micro-B provides a reliable middle ground between consumer connectors and heavy-duty military interfaces.

Table of Contents

• Overview
• Key Features & Benefits
• Typical Applications
• Performance & Design Highlights
• Design Considerations & Integration Tips
• Resources & Related Solutions

Overview

The Micro-Bayonet Connector Series is a cylindrical, metal, micro bayonet circular connector family optimized for low power and signal interconnects. It was developed for applications where electrical performance, EMI control, and environmental sealing are essential, but traditional mil-grade circulars are over-specified or cost prohibitive.

Each micro bayonet circular connector combines a robust 1/4-turn triple bayonet coupling with an internal EMI ground spring to deliver excellent shell-to-shell conductivity. High-density insert patterns with size 22D contacts support up to 15 circuits in a very small footprint, making Micro-B ideal for compact control boxes, sensor modules, and distributed I/O in space-constrained equipment.

Micro-B is engineered as an alternative to D-sub and other rectangular signal connectors, offering better sealing, more robust strain relief, and faster, tool-less mating while still aligning with cost and packaging requirements for industrial and transportation markets. For many designs, a single micro bayonet circular connector can replace multiple legacy signal interfaces while improving environmental performance.

Key Features & Benefits

• Compact, high-density circular platform — Small shell size with high density insert patterns (up to 15 contacts) helps shrink enclosure size and PCB real estate while maintaining clear routing for low power and signal circuits in a micro bayonet circular connector format.
• Triple bayonet 1/4-turn coupling — Positive, 1/4-turn bayonet mating delivers quick connect/disconnect and strong vibration resistance, ideal for frequent servicing and field maintenance.
• Rugged metal shell construction — Aluminum shells provide a high strength-to-weight ratio and support multiple conductive plating options, including finishes rated for up to 500 hours of salt spray.
• Excellent EMI performance — An internal EMI ground spring and shell-to-shell bonding support robust shielding performance when used with appropriate shielded backshells and cable.
• High signal density with size 22D contacts — Stamped and formed size 22D contacts simplify harnessing and allow more circuits in a smaller micro bayonet circular connector envelope.
• Tool-less, fast mating — Bayonet coupling with clear tactile feedback reduces mating time and minimizes the risk of incomplete engagement in production and service environments.
• Flexible termination options — Crimp contacts, tape-and-reel options for automated processing, and PCB-tail variants support cable assemblies, harness manufacturing, and direct board termination.
• Versatile mounting styles — Available in in-line plug and 2-hole flange receptacle configurations to support cable-to-panel and cable-to-device architectures.
• Harsh-environment performance — Operating temperature range from -40 °C to +125 °C, high shock and vibration resistance, and ingress protection up to IP67 in the mated condition with sealed backshells.
• Compliance and safety — RoHS and REACH compliant, designed to meet smoke, toxicity, and flammability requirements, with UL certification support for global use.
• Cost-effective alternative to D-sub — Provides environmental sealing, EMI performance, and circular ergonomics while staying within industrial cost targets, often allowing one micro bayonet circular connector to replace several legacy signal connectors.

Typical Applications

Micro-Bayonet micro bayonet circular connector solutions are used wherever compact, reliable signal and low current power connections are needed in harsh or semi-harsh environments, including:

• Factory automation and robotics — I/O modules, servo drives, sensors, encoders, and control boxes exposed to vibration, dust, and washdown environments where a sealed micro bayonet circular connector improves uptime.
• Hybrid and electric vehicles — Low-current control wiring, sensor and feedback harnesses, charging station electronics, and auxiliary subsystems where sealed, shielded micro bayonet circular connector interfaces are required.
• Industrial instrumentation — Measurement systems, analyzers, and portable instruments that must survive field handling and outdoor conditions while maintaining stable signal integrity.
• Telecommunications and networking — Outdoor radio units, small cells, and support electronics where compact micro bayonet circular connector interfaces reduce panel space and improve sealing.
• Medical and lab equipment — Compact instruments, pumps, and diagnostic equipment that benefit from quick-connect circular interfaces with reliable EMI performance.
• Security, surveillance, and vision systems — Cameras, controllers, and sensor nodes exposed to dust, moisture, and temperature cycling that benefit from rugged micro bayonet circular connector terminations.
• Unmanned platforms and mobility equipment — UAV subsystems, AGVs, and autonomous machines that need lightweight, vibration-resistant signal interconnects.

For broader system architectures, Micro-Bayonet can be combined with higher power circulars and rectangular power interfaces across Amphenol Industrial’s Factory Automation, eMobility, and Additional Industries portfolios.

Performance & Design Highlights

Electrical performance

• Recommended operating voltage: up to 250 VAC (RMS) for typical low power and signal applications using size 22D contacts in a micro bayonet circular connector.
• Current rating: up to 3 A per size 22D contact (application dependent).
• Contact configurations: high-density layouts supporting 7, 10, or 15 contacts in a compact shell.
• Insulation resistance: 1000 MΩ minimum at 500 V (typical test condition).
• Contact resistance: 22 mΩ maximum per contact helps maintain low signal loss.

Mechanical performance

• Mating cycles: rated for approximately 500 mating/unmating cycles with appropriate plating.
• Coupling system: triple bayonet 1/4-turn mechanism provides quick engagement with strong mechanical retention.
• Wire sizes: supports typical signal wire ranges such as 22–26 AWG for compact harnessing.
• Keying options: multiple keying orientations help prevent mis-mating when several similar micro bayonet circular connector interfaces share a panel.

Materials & construction

• Shell material: aluminum alloy for high strength and low weight.
• Contact material and plating: copper alloy contacts with tin and/or gold plating options for reliable conductivity and corrosion resistance.
• Insulator material: high-performance engineering plastic designed for dimensional stability and dielectric performance across the operating temperature range.
• EMI components: conductive copper alloy EMI rings and optional shield-termination hardware for 360° cable shielding.
• Plating options: conductive platings including gray ZnNi and electroless nickel to support salt-spray performance up to 500 hours.

Environmental & standards

• Operating temperature range: -40 °C to +125 °C for use in demanding industrial and transportation environments.
• Ingress protection: up to IP67 in the mated condition when used with sealed backshells and appropriate cable preparation. For a general overview of the IP rating system, see the IEC IP ratings guide.
• Corrosion resistance: shell plating options tested to withstand extended salt-spray exposure.
• Compliance: RoHS and REACH compliant, designed to meet smoke, toxicity, and flammability requirements; UL support for global approvals.

Design Considerations & Integration Tips

• Choose the right insert pattern — Match the number of contacts to your signal count and future expansion needs. High-density layouts help consolidate multiple D-sub or terminal connections into a single micro bayonet circular connector.
• Plan for shielding and grounding — For noisy environments, specify shielded cable and an appropriate EMI backshell so that the internal EMI spring and shell-to-shell bonding can deliver full shielding performance.
• Consider keying and coding — When multiple Micro-B connectors are used on the same panel or box, select unique keying orientations to prevent mis-mating during assembly and service.
• Verify IP and environmental requirements — For washdown or outdoor use, pair the connector with sealed backshells and cable glands, and confirm that the complete assembly meets your target IP rating and temperature profile.
• Optimize harness manufacturing — Take advantage of stamped-and-formed contacts and tape-and-reel options to support automated crimping and high-volume harness production.
• Allow clearance for bayonet coupling — Provide enough hand access and rotation space for the 1/4-turn bayonet coupling, especially on densely populated panels.
• Related circular connector families — Consider pairing Micro-B with other Amphenol Industrial circular solutions such as:
  • PT Series — metal bayonet circular connectors for power and signal.
  • UPT Connector Series — plastic bayonet circulars for power and signal in harsh environments.
  • Max-M12 — high-speed M12 circulars for data and signal.
  • LPT Series — quarter-turn power and signal circular connectors for demanding industrial applications.