The RMLH2577-054 is a floating self-locking barrel nut used in aerospace structural assemblies where access is limited to one side and high-vibration resistance is required. It is part of the NSN 5310-01-136-8353 hardware family and is designed to provide a captive, self-aligning threaded anchor for mating bolts in aircraft structures.

The nut features a cylindrical barrel body with a floating internal threaded element, allowing limited movement for alignment during assembly. Its prevailing-torque all-metal locking design ensures secure fastening under vibration, thermal cycling, and dynamic load conditions typical in airframe applications.

This specific variant is commonly used in aircraft structural joints, access panels, and frame assemblies where blind fastening is required and standard nuts cannot be accessed or held during installation.

Key features include:

Aerospace floating barrel self-locking nut (NAS/NSN standard hardware)
NSN: 5310-01-136-8353
Thread: UNJF 3/8-24 (Class 3B internal thread)
All-metal prevailing torque locking mechanism
Floating insert for alignment during bolt installation
Designed for blind fastening applications in airframe structures
Cadmium/chromate corrosion protection (QQ-P-416 Type II Class 3)
High temperature resistance up to ~450°F (232°C)
Vibration-resistant locking suitable for rotorcraft and fixed-wing aircraft
Commonly used in structural brackets, skins, and internal assemblies
Made to aerospace standards with controlled hardness (36–43 HRC range)
Replaces standard fixed nuts where installation access is restricted