MS14144L6 - Bombardier OEM Aerospace Nut Castled Self Locking .375-24 PR

MS14144L6 – Bombardier OEM Aerospace Nut Castled Self Locking .375-24 PR

Available now on the Airparts.aero Marketplace.

Overview

The MS14144L6 is a military-standard, castellated, all-metal self-locking nut, representing one of the most secure and reliable fastening solutions in the aerospace industry. This flight-critical component is engineered to provide redundant locking mechanisms for use in high-temperature, high-vibration, and safety-critical applications. Manufactured from high-strength, corrosion-resistant steel and specified for use on Bombardier and other high-performance aircraft, the MS14144L6 combines the prevailing torque of a self-locking nut with the positive mechanical lock of a castellated nut and cotter pin, ensuring absolute fastening integrity.

Key Features

• Redundant Locking System: Features two independent locking mechanisms. First, an all-metal, deformed-thread design creates prevailing torque to resist loosening from vibration. Second, the castellated slots on top of the nut are designed to align with a hole in the bolt, allowing for the installation of a cotter pin for a positive, mechanical lock.
• High-Temperature CRES Construction: The "L" designation specifies that this nut is fabricated from a high-strength, Corrosion-Resistant Steel (CRES), such as A286. This material provides excellent strength retention and corrosion resistance at continuous operating temperatures up to 450°F (232°C) and beyond.
• All-Metal Design: The absence of any non-metallic inserts (like nylon) makes this nut impervious to high temperatures, hydraulic fluids, and other solvents that would degrade lesser locknuts.
• High-Strength for Critical Joints: Engineered with the tensile strength required to properly preload high-strength AN, NAS, and MS structural bolts, creating a rigid and fatigue-resistant joint.
• MS Certified Standard: As a certified Military Standard part, it guarantees the material composition, dimensional tolerances, heat treatment, and locking performance required for the most flight-critical applications.

Technical Specifications

• Standard: MS14144 (Nut, Self-Locking, Castellated, Hexagon, 450°F)
• Full Part Number: MS14144L6
• Component Type: All-Metal, Castellated, Prevailing Torque Self-Locking Nut
• Material (L): Corrosion-Resistant Steel (CRES), e.g., A286
• Finish: Passivated (with a dry film lube often applied to threads)
• Thread Specification: 3/8-24 UNJF-3B
  • Nominal Diameter: 3/8 inch (0.375 inches)
  • Threads Per Inch: 24 (Fine Thread)
• Wrench Size: 9/16 inch
• Maximum Operating Temperature: 450°F (232°C)

Aircraft Compatibility

The MS14144L6 is a high-performance fastener specified for the most critical structural joints on transport-category and high-performance aircraft, such as those manufactured by Bombardier.

• Common Aircraft Platforms:
  • Bombardier: Challenger, Global, and CRJ series
  • Textron Aviation: Cessna Citation and Beechcraft King Air series
  • Other commercial and military jet aircraft.
• Common Applications:
  • Engine Mounts & Pylons: Securing the engine mount assembly to the firewall and wing structures.
  • Primary Flight Controls: Used on hinge points and actuator attachments for stabilizers, elevators, and ailerons.
  • Landing Gear Systems: Fastening major structural components within the landing gear and retraction mechanisms.

Applications

The MS14144L6 is the specified fastener where a joint failure is not an option:

• Fail-Safe Fastening: The dual-locking system provides the ultimate security, making it the choice for joints where a loss of preload could have catastrophic consequences.
• High-Temperature & High-Vibration Zones: Specifically designed to maintain its integrity and locking action in the most hostile environments on an aircraft, such as firewall forward.

Why Choose MS14144L6?

For the most critical bolted joints on an aircraft, engineers demand redundant safety features. The MS14144L6 provides this redundancy. The self-locking feature prevents the nut from vibrating loose, while the cotter pin provides a positive, physical lock that ensures the nut cannot back off, even if the preload is somehow diminished. Using a genuine, certified MS14144L6 is the only way to ensure you are installing a fastener that meets the material and performance requirements for these ultimate, safety-of-flight applications.

Order Your MS14144L6 Nuts Now

Secure your aircraft's most flight-critical joints with the ultimate in redundant locking technology. Visit Airparts.aero to order your MS14144L6 castellated self-locking nuts today.

The MS14144L6 represents a "belt and suspenders" approach to aerospace fastening. The self-locking feature is achieved by deforming the upper threads of the nut into a non-circular shape, creating a prevailing torque that resists vibration. The castellated feature, a series of slots on top of the nut, allows for the insertion of an MS24665 cotter pin through a hole drilled in the mating bolt. Standard procedure requires tightening the nut to the specified torque value, then advancing it slightly to the next available slot that aligns with the bolt hole. The installation of the cotter pin then creates a positive lock. This dual system ensures that even in the unlikely event that extreme vibration and thermal cycling were to overcome the prevailing torque, the nut is physically prevented from rotating off the bolt.

Note: This is a flight-critical structural component. It must be used with a bolt that has a drilled shank for a cotter pin. Installation requires the use of a calibrated torque wrench. After achieving the specified torque, the nut may only be tightened further (never loosened) to align the castellations with the hole. A new cotter pin must be used for every installation.