Bearings are employed in countless areas of aircraft and spacecraft, supporting smooth movement for turbine shafts, landing gear, and more. Like any item intended for aerospace use, bearings are required to comply with multiple standards that address geometric tolerances, material quality, inspection methods, and supply chain traceability. In this blog, we will cover some of the most notable standards and certifications that aviation bearings are governed by to assure they perform as intended.
The International Organization for Standardization (ISO) develops global standards across industries, with ISO 492 specifically defining dimensional accuracy, permissible size deviations, and running tolerances for radial rolling bearings. In the United States, the American Bearing Manufacturers Association (ABMA) presents equivalent requirements under the ANSI/ABMA designation, with ANSI/ABMA 20 mirroring ISO 492 to ensure consistency between domestic and international practices. While these are important baselines for bearing quality, they are intended for general-purpose bearings, rather than those utilized in aerospace.
Because aerospace bearings operate under stresses and conditions well beyond the scope of broad tolerance standards, the ISO issued ISO 14190 in 1998, a specification dedicated to airframe rolling bearings. This standard defined requirements for design, inspection, and testing of bearings in applications subject to oscillating motion or slow rotation under sustained load. Although ISO has since withdrawn ISO 14190, its provisions are still referenced in adapted or equivalent forms.
ASTM International develops material guidelines that underpin aerospace bearing design, encompassing chemical composition, mechanical properties, and heat-treatment processes. These requirements apply to both traditional bearing steels and hybrid materials, verifying that they exhibit uniform hardness, fatigue resistance, and unsusceptibility to corrosion.
The Society of Automotive Engineers (SAE) International issues various AS standards that provide detailed technical and performance criteria for many bearings used across aviation and defense sectors. For example, AS81820 dictates requirements for self-lubricating, spherical plain bearings, while AS14101 covers airframe control ball bearings. Recognized globally, SAE AS standards establish uniform performance and safety features for bearings supplied by different manufacturers.
Many major aerospace manufacturers like Boeing and Lockheed Martin maintain internal standards that supplement industry benchmarks with additional criteria tailored to unique design philosophies, aircraft models, or proprietary systems. Therefore, bearings designed to meet OEM internal standards are subject to additional testing and certification protocols to confirm their compatibility with specialized assemblies.
Developed by SAE International and overseen by the International Aerospace Quality Group (IAQG), the AS9100 standard defines a comprehensive quality-management system for aerospace manufacturers. It builds upon ISO 9001, the globally recognized framework for quality management, adding aviation-specific design, production, inspection, and material traceability criterion. Certification to AS9100 is recognized by leading aerospace regulators, including the FAA, EASA, NASA, and the U.S. Department of Defense, providing assurance that all aerospace bearings and other relevant items are produced under rigorously controlled and standardized processes.
To address the distribution side of the supply chain, the AS9120 standard extends AS9100 principles to aerospace distributors. Accredited certification bodies verify compliance in regards to traceability, record control, awareness of airworthiness certification, and handling procedures, with awarded distributors being recognized for offering aerospace components that maintain certified quality as they move through the supply chain.
AS9102, created by SAE International, governs First Article Inspection (FAI) procedures for aerospace components, mandating detailed documentation of material traceability, dimensional inspection, and verification of production processes. This guarantees that new bearing designs or major manufacturing changes comply with intended specifications before entering service.
Nondestructive testing (NDT) methods are standardized through organizations like ASTM International, ISO, and the American Society for Nondestructive Testing (ASNT). These establishments set practices for fluorescent penetrant testing, magnetic particle testing, eddy-current testing, and ultrasonic examination methods that are used to detect subsurface flaws, inclusions, or grinding burns that could cause bearings to fail in service. By standardizing approaches to these methods, quality can be consistently confirmed.
In all, aerospace bearings are held to various standards that define everything from their design to supply-chain expectations, ensuring that bearings can withstand the rigors of flight. To purchase bearings that adhere to these exacting requirements, it is absolutely vital to use a dependable procurement platform.
Here on NSN World, we offer access to a wide range of aviation-compliant bearings and various other products sourced from reputable manufacturers and suppliers. Through this website, users are able to browse parts by designations like NSN, manufacturer, part type, and more, as well as easily submit quote requests online to receive curated solutions. To see how we can help you procure all the aircraft components you need with confidence, get in touch with our experts today.
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