MS28782-6 - Textron Aviation OEM Retainer Ring

MS28782-6 – Textron Aviation OEM Spiral Retaining Ring (0.375" Bore)

Available now on the Airparts.aero Marketplace.

Overview

The MS28782-6 is a high-strength, military standard spiral wound retaining ring, supplied with the full certification and traceability of Textron Aviation as an Original Equipment Manufacturer (OEM) component. This advanced fastener is coiled from flattened carbon spring steel wire and is engineered for the precise axial positioning and retention of components within a 0.375-inch (3/8") diameter bore or housing. It provides a uniform, 360-degree retaining shoulder.

Manufactured in strict accordance with MS28782, this multi-turn ring is installed by winding it into a simple rectangular groove. Unlike a conventional snap ring, its gapless design ensures uniform radial force and continuous contact with the groove, enhancing load capacity and fatigue resistance. As a genuine Textron Aviation part, it guarantees the precise material properties and dimensions required for airworthy assembly on Cessna, Beechcraft, and Hawker aircraft.

Key Features

• Genuine Textron Aviation OEM Part: Guarantees the part is the factory-specified and fully certified component, ensuring correct performance and airworthiness for Textron aircraft.

• Military Specification Compliance: Manufactured and tested in strict accordance with MS28782 / NASM28782, guaranteeing material properties, dimensional accuracy, and performance.

• Spiral Wound, Multi-Turn Design: Typically features two turns, providing a continuous, gapless 360-degree retaining shoulder for uniform load distribution and superior strength.

• High-Strength Carbon Spring Steel: Fabricated from certified carbon spring steel (per SAE 1070-1090), heat-treated for high tensile strength and elasticity.

• Designed for Internal Grooves (Bores): Specifically engineered for installation within a 0.375" housing or bore to retain components axially.

• Phosphate Coated Finish: Provides corrosion resistance per MIL-DTL-16232, Type Z, Class 2.

Technical Specifications

• Part Number: MS28782-6

• Component Type: Spiral Wound Retaining Ring (Internal)

• OEM Authority: Textron Aviation

• Governing Specification: MS28782 / NASM28782

• Material: Carbon Spring Steel (per SAE 1070-1090)

• Finish: Phosphate Coat per MIL-DTL-16232, Type Z, Class 2

• For Housing Bore Diameter: 0.375 inches

• Groove Diameter (Ref): 0.406 inches

• Ring Free Outside Diameter (Approx): 0.420 inches

• Wire Cross-Section: Per MS28782 standard.

Aircraft Compatibility

As a Textron Aviation OEM part conforming to a military standard, this retaining ring is specified for numerous applications across their product lines.

• Primary Textron Aviation Platforms:

  • Cessna Piston Aircraft

  • Beechcraft Piston Aircraft

  • Cessna Caravan Series

  • Cessna Citation Business Jets

  • Beechcraft King Air Series

  • Hawker Business Jets

• General Aerospace Usage: Used across all sectors where a certified MS28782-6 ring is required.

Note: Verification of applicability is the responsibility of the installer. Always consult the current version of the aircraft or component Illustrated Parts Catalog (IPC) and maintenance manual to confirm part number eligibility.

Applications

• Axial retention of bearings within gearbox housings, accessory drives, and actuators.

• Securing seals, glands, and pistons within hydraulic and pneumatic components.

• Positioning gears, sprockets, and pulleys within housings.

• Any mechanical assembly requiring a secure, low-profile internal retaining ring for a 3/8" bore.

Why Choose this MS28782-6?

This component provides the dual assurance of meeting the public military specification and the specific endorsement of Textron Aviation. The failure of a retaining ring can lead to catastrophic component disassembly. Using the genuine OEM MS28782-6 guarantees the correct material, heat treatment, and dimensions required for the ring to provide its full rated thrust load capacity safely and reliably, as specified by Textron engineers.

The engineering advantage of the MS28782-6 spiral retaining ring lies in its superior stress distribution. Unlike a standard snap ring that contacts the groove at only three points, the multi-turn spiral design provides continuous 360-degree contact. This distributes the axial thrust load uniformly around the entire groove circumference, significantly reducing peak stress in both the ring and the groove. This allows the spiral ring to often handle higher thrust loads and offers increased fatigue life for the groove itself compared to a snap ring of equivalent size. The slight radial compression during installation ensures the ring exerts a continuous outward spring force, keeping it dynamically stable and securely seated under vibration.

Note: This is a flight-critical hardware component. Installation and removal typically require specialized tools or techniques to wind the ring into or out of its groove without overstressing or permanently deforming it. Re-use is generally permissible if the ring remains within its specified dimensional tolerances and shows no signs of damage or deformation. Always consult the component maintenance manual for specific instructions.

Documentation

The military standard governing this part is publicly available through the Department of Defense ASSIST database. OEM-specific application data is contained within the Textron Aviation maintenance and parts manuals.

• ASSIST Document Summary Page for MS28782: http://quicksearch.dla.mil/qsDocDetails.aspx?ident_number=45934