MS14103-5 - Self-Lubricating Self-Aligning Low Speed Wide Grooved Outer Ring Bearing

MS14103-5 – Mil-Spec Self-Lubricating Spherical Bearing

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Overview

The MS14103-5 is a military-specification, self-aligning, and self-lubricating plain spherical bearing, manufactured in strict accordance with the MS14103 standard. This is a flight-critical component used across the entire aerospace industry for high-load, low-speed, and oscillatory pivot applications where misalignment must be accommodated and maintenance-free operation is required. It is an advanced sliding-contact bearing, not a rolling-element bearing, and serves as a durable, low-friction pivot point in systems like flight controls, landing gear linkages, and actuators.

The bearing's construction features a hardened, corrosion-resistant steel outer ring with a proprietary, woven Polytetrafluoroethylene (PTFE) liner bonded to its inner surface. The hardened, corrosion-resistant steel inner ball pivots against this self-lubricating liner, a design which completely eliminates the need for grease or external lubrication. The grooved outer ring is specifically designed for V-groove staking, a secure and permanent method of installation. For any aerospace application requiring a robust, maintenance-free, and misaligning pivot joint, the certified MS14103-5 is the definitive engineering solution.

Key Features

• Mil-Spec Certified: Manufactured and inspected in strict accordance with the MS14103 military standard, guaranteeing material, dimensional, and load-rating integrity.

• Self-Lubricating PTFE Liner: Features a woven fabric liner of PTFE (Teflon®), providing a continuous, low-friction surface that eliminates the need for lubrication throughout its service life.

• Self-Aligning Spherical Design: The ball-and-socket geometry allows the inner ball to misalign relative to the outer ring, accommodating structural flex and preventing binding in critical linkages.

• Corrosion-Resistant Steel Construction: Both the inner ball and outer ring are fabricated from high-strength, precipitation-hardened or through-hardened stainless steel for maximum strength and corrosion resistance.

• Grooved Outer Ring for Staking: The outer diameter features a precision-machined V-groove designed to accept a staked housing lip, providing a secure, positive retention of the bearing.

Technical Specifications

• Part Number / Specification: MS14103-5

• Component Type: Plain Spherical Bearing, Self-Aligning, Self-Lubricating

• OEM Manufacturer: Certified Mil-Spec Manufacturer

• Bore Diameter (-5): 5/16 inch (0.3125")

• Outer Ring Material: Corrosion-Resistant Steel (CRES), e.g., 17-4PH.

• Inner Ball Material: Corrosion-Resistant Steel (CRES), e.g., 440C, through-hardened.

• Liner System: Woven PTFE fabric with a high-strength bonding resin.

• Governing Specification: MS14103, NASM14103.

Aircraft Compatibility

• Universal Aerospace Application: This is a standard mil-spec bearing used by virtually every major airframe manufacturer in the world where a bearing with these specifications is required by engineering drawings. Applicable aircraft families include, but are not limited to, those from:

  • Boeing, Airbus, Lockheed Martin, Textron Aviation (Cessna, Beechcraft), Bombardier (Learjet, Challenger, Global), Gulfstream, Piper, and military aircraft.

Note: The correct bearing for any application must be verified against the specific aircraft or component Illustrated Parts Catalog (IPC) or maintenance manual.

Applications

• Flight Control Systems: Used at the pivot points for ailerons, elevators, rudders, flaps, spoilers, and trim tab linkages.

• Landing Gear: A critical component in retraction actuators, torque links, shock strut attachments, and steering mechanisms.

• Actuator Mounts: Provides a misaligning pivot for hydraulic, pneumatic, and electromechanical actuators.

• Airframe Structure: Used in pylon-to-wing attachments, engine mounts, and other structural joints with complex motion.

Why Choose MS14103-5?

The failure of a bearing in a flight control or landing gear system would be catastrophic. The certified MS14103-5 is an engineered system where the materials, surface finishes, and liner technology are all designed to work in concert to handle specific loads and environmental conditions. A non-certified, commercial-grade bearing may use an inferior injection-molded or bonded-particulate liner that can fail or wear out rapidly under the high static loads and vibratory dither common in aircraft. It may be made from materials without the required strength or corrosion resistance. Sourcing a fully traceable, mil-spec bearing is the only way to ensure the safety and airworthiness of these critical moving joints.

The engineering science behind the MS14103-5's self-lubricating liner is a triumph of tribology and composite materials. The liner is not a simple coating; it is a complex, multi-layered system. It typically consists of a woven fabric of Polytetrafluoroethylene (PTFE) fibers and other high-strength fibers (like glass, aramid, or polyester) that is impregnated with and bonded to the outer race by a high-strength thermosetting resin (such as a phenolic or epoxy). The weave of the fabric creates a durable matrix that mechanically locks the low-friction PTFE in place, preventing it from cold-flowing or extruding under the high compressive loads a bearing experiences in service. During operation, a microscopic layer of PTFE is transferred from the liner to the surface of the inner ball, creating a dynamic, self-renewing, solid-film lubricant with an extremely low coefficient of friction. This composite structure provides both the high load-carrying capacity of a metal bearing and the maintenance-free, low-friction properties of a lubricated joint.

Note: The MS14103-5 is a flight-critical component. Installation requires specialized tooling and techniques. It is typically a press fit into the housing and must be installed using a properly designed arbor that applies force only to the outer ring to avoid damaging the liner. After installation, the housing must be properly staked into the bearing's V-groove using a calibrated staking tool. Improper installation can lead to premature failure of the bearing or the surrounding structure.

Documentation

• MS14103 Standard: The military standard sheet (e.g., NASM14103) defines all dimensional, material, and performance requirements for this series of bearings and is publicly available through various online mil-spec libraries.