Amphenol 2M801, 2M804 and 2M805 are rugged micro-miniature circular connectors designed to reduce size and weight compared with conventional MIL-DTL-38999 connectors. Their primary difference is the coupling mechanism: 2M801 uses a heavy dual-start ACME thread, 2M804 uses a push-pull quick-disconnect interface, and 2M805 uses a faster tri-start threaded coupling.

For new high-vibration aerospace or military designs, 2M805 is generally the best starting point. Choose 2M804 when rapid one-handed disconnection is essential, and retain 2M801 primarily for compatibility with existing equipment and cable assemblies.

Quick Comparison

What Are Amphenol 2M Connectors?

The Amphenol 2M family provides D38999-type rugged connectivity in a substantially smaller package. Depending on the series and insert arrangement, the connectors support signal, power and high-speed data contacts for applications where size, weight and panel space are restricted.

Typical benefits include:

• Micro-miniature circular construction

• High contact density

• Removable crimp contacts

• Environmental sealing

• EMI/RFI shielding

• Rugged keying and polarization

• Multiple plug and receptacle styles

• Lightweight aluminum shell options

• Low-profile and right-angle accessories

• Support for UAV, aircraft and military equipment

The 2M series is suitable for SWaP-focused designs—systems where size, weight and power must be minimized without giving up environmental reliability.

Amphenol 2M801: Dual-Start ACME Thread

The 2M801 series uses a heavy dual-start ACME threaded coupling. Amphenol describes it as the most durable member of the standard 2M family, with applicable configurations supporting up to 2,000 mating cycles.

Main characteristics

• Dual-start ACME threaded interface

• Rugged coupling threads

• Ratcheting and anti-decoupling plug options

• High-speed configurations available

• Up to 2,000 mating cycles

• Strong resistance to shock and vibration

• Established installed base

Advantages

The heavy ACME thread provides a durable mechanical interface for equipment subjected to repeated mating, mechanical wear or high vibration. It is especially useful when maintaining compatibility with existing 2M801 cable assemblies and system interfaces.

Amphenol also offers high-speed 2M801 configurations for USB 3.0, eSATA and other data-bus applications where panel space is limited.

Limitations

Amphenol now considers 2M801 a legacy series for many new-design decisions. Compared with 2M805, it generally requires more rotation to mate and does not include the same improved EMI grounding-band design.

Best applications

• Existing 2M801 equipment

• Maintenance and replacement cable assemblies

• Rugged industrial systems

• Legacy aircraft electronics

• Military platforms requiring established interfaces

• Applications with high mating-cycle requirements

Amphenol recommends selecting 2M801 when compatibility with existing connectors, equipment or cables is the deciding factor.

Amphenol 2M804: Push-Pull Quick-Disconnect

The 2M804 series uses a push-pull coupling system. It is intended for equipment that must be connected and disconnected quickly without rotating a coupling nut.

Main characteristics

• Push-pull quick-disconnect interface

• Rapid one-handed mating and release

• Waterproof and dustproof construction

• Excellent EMI shielding

• D38999-type immersion performance

• Customizable separation force

• Contact arrangements supporting up to 85 signals

• Multiple panel-mounting options

Advantages

Push-pull coupling makes 2M804 the quickest of the three series to connect and disconnect. This is useful for wearable, portable and field-service equipment where the operator may be wearing gloves or may need to release the cable rapidly.

The customizable separation force allows the interface to be configured around equipment-retention and operator-safety requirements.

Limitations

A push-pull interface may not be appropriate where cable pulling, snagging or severe vibration could produce unintended axial release. The required separation force and cable strain relief must therefore be specified carefully.

Best applications

• Soldier-worn tactical equipment

• C4I communication systems

• In-flight entertainment equipment

• Portable military electronics

• Field-service test equipment

• Medical or instrumentation systems requiring quick disconnect

• Applications requiring frequent cable changes

Amphenol describes the 2M804 as a rugged push-pull connector designed for soldier-worn tactical systems, with waterproofing, dust protection and EMI resistance.

Amphenol 2M805: Tri-Start Threaded Coupling

The 2M805 series uses a tri-start threaded coupling based on the operating principles of MIL-DTL-38999 Series III. It is designed for new micro-miniature systems requiring fast threaded mating, strong shielding and high vibration resistance.

Main characteristics

• Tri-start threaded coupling

• Faster threaded mating than 2M801

• Excellent EMI shielding

• Nickel-plated grounding spring

• Superior vibration resistance

• Waterproof construction

• High-speed options

• Insert arrangements with up to 130 contacts

• Less than half the size and weight of many corresponding D38999 solutions

Advantages

The tri-start thread advances farther with each turn, reducing the rotation required to fully mate the connector. It retains the security of threaded coupling while improving installation and maintenance speed.

The grounding spring increases shell-to-shell conductivity and supports better EMI shielding. This makes 2M805 attractive for compact avionics, high-speed data and noise-sensitive systems.

Limitations

2M805 should not automatically be treated as a drop-in replacement for 2M801. The coupling interface, part numbering, backshells and mating components must all be checked.

Best applications

• New UAV and aircraft designs

• High-vibration avionics

• Missile and guidance systems

• Radar and electronic warfare

• Military ground vehicles

• Robotics and autonomous platforms

• High-speed sensor systems

• Compact communication equipment

Amphenol positions 2M805 as its evolved Micro 38999 platform, combining tri-start coupling, enhanced grounding and D38999-type environmental performance in a smaller package.

Coupling Mechanism Comparison

FAQ

What is the main difference between 2M801 and 2M805?

2M801 uses a dual-start ACME thread. 2M805 uses a faster tri-start thread and adds a grounding spring for improved shell conductivity and EMI shielding.

Is 2M804 threaded?

No. It uses a push-pull quick-disconnect mechanism.

Which series is best for new UAV designs?

2M805 is usually the preferred starting point because it combines low weight, strong vibration resistance, waterproofing and improved EMI shielding.

Which series is best for soldier-worn equipment?

2M804 is designed specifically around push-pull operation and portable tactical applications.

Is 2M801 obsolete?

Amphenol describes it as a legacy series, but it remains relevant for maintaining existing equipment and cable compatibility. Check the lifecycle status of the exact part number.

Can 2M801, 2M804 and 2M805 use the same accessories?

Some accessory families are offered across all three series, but compatibility depends on the exact shell style, rear interface and part number. Do not assume accessories are interchangeable.

Conclusion

Choose Amphenol 2M801 for installed-base compatibility and durable dual-start ACME coupling, 2M804 for the fastest push-pull disconnection, and 2M805 for new high-vibration designs requiring tri-start threaded coupling and enhanced EMI shielding.

 DataStorageIC supplies Amphenol 2M micro-miniature connectors for prototype, maintenance and production requirements. Contact us to confirm part-number compatibility, stock, lead time and quotation requirements.