MRC hybrid ceramic ball bearings combine traditional steel rings with nonconductive silicon nitride (ceramic) balls, offering inherent insulating properties to prevent electrical arcing, excessive noise, premature lubricant aging, and associated surface damage to raceways. They provide drop-in replacement solutions within existing design envelopes in such applications as large variable-speed electric motors where electric arcing is prevalent. Compared with all-steel bearings, the company says, these bearings are lighter, harder, and more durable. They can run at higher speeds and lower operating temperatures and exhibit high wear resistance. The ceramic balls are 40% less dense than steel balls, and the reduced centrifugal force and friction allow them to run faster and cooler. Standard MRC hybrid ceramic ball bearings are available from stock with bore diameters from 30 to 180 mm. They can be engineered with seals and shields or otherwise customized through the MRC made-to-order (MTO) warranted products program. CAD drawings of standard types are available for free download at www.skfusa.com/mrc.