What Is the Difference Between Steel and Ceramic Bearings?

A bearing is a cylindrical piece of machinery that functions to reduce friction between two flat surfaces in contact. Within aircraft, bearings function to hold journals and rods in place and absorb shock during machine operations and landings. They work to prevent damage from heat and pressure by reducing friction between two points of contact. Bearings also serve the purpose of protecting vital components of aircraft, including engines, actuators, and missile launchers by allowing for greater mobility (sometimes a full 360 degrees). The part of machinery that needs bearing support is inserted into the circular opening of the bearing, and the bearing rotates around it.

When purchasing bearings for an aircraft, an important distinction between bearing materials to take into consideration is the function of steel bearings in comparison to the function of ceramic bearings. One of the most common concerns is that ceramic bearings offer less friction reduction than their steel counterparts. In reality, steel and ceramic are relatively interchangeable in their function as balls within roller bearings; however, the bearing clearance created by ceramic bearings is usually smaller than that created by steel bearings. The hybrid ceramic balls often create a C3 bearing clearance versus that of steel bearings which is often a CN clearing, both of which are common terms to describe bearing clearances. The bigger bearing clearance allows for greater expansion under higher temperatures, making the metal bearing a more optimal choice for enduring temperature changes throughout flight without cracking or bearing seizures. Additionally, the outer cage of steel bearings is more often created in a costly ribbon pattern, while the outer cage of ceramic bearings is more often created from rubber, which pops off, deforms, and creates more friction under higher pressures.

The main reason metal bearings should be prioritized for aircraft is that the risk of wear and damage is lesser than that of ceramic bearings. Although the initial differences in power lost to friction in each type are very small, long term use is less reliable in ceramic bearings. The main concern surrounding bearings are the differences in bearing seals and lubricants which create the greatest difference in power lost to friction. Bearing friction increases as bearings wear down, and ceramic bearings are shown to wear down more rapidly than metal bearings.

When you require particular aviation components, Nascent Aero is your one-stop-shop online distributor of various parts and components catering to the aerospace, defense, and electronic sectors. We also distribute new, used, and hard-to-find parts across the globe! Nascent Aero is the future of part procurement, presenting customers access to countless components that may be reliably utilized for a variety of industries and applications. With our unyielding dedication to upholding quality, we choose to only stock items from leading global manufacturers that we trust. With AS9120B, ISO 9001:2015, and FAA AC 00-56B certification and accreditation, customers can rest assured that our parts are guaranteed for fit, form, and function. To receive a rapid quote for your comparisons on any item of interest, we invite you to take advantage of our Instant RFQ service to receive a comprehensive quote in as little as 15 minutes or less.

1. albert harris
2. Posted on April 22, 2022
bearings