Angular Contact Ball Bearings - ROBUST Series of Ultra high-Speed ACBB NSK's ROBUST Series of Ultra high-Speed Angular Contact Ball Bearings for machine tool main spindles. These bearings offer improved thermal robustness, low heat generation, improved seizure rates and low noise. This ensures that machine tools can operate at ultra-high speeds, increasing manufacturers productivity & reduced energy costs. Product Features • ROBUST design - For better durability under fluctuating conditions: Lowest temperature rise & improved thermal robustness • SHX bearing steel improves seizure & wear resistance, fatigue life & grease life time • Rolling element material can be steel or ceramic air lubrication • Bearing with Spinshot™II oil air noise (3 to 4system: ultra high speed & reduced dB quieter) Condition Description • High Speed • High Temperature • ROBUST Series than conventional super precision bearing, • 20%tofaster faster up 80% • Ultra high-speed possible with position preload (2.5 Mil. dm* n) • ROBUST Series with Polyamid cage • Grease lubrication with larger internal space • Lower friction, shorter running-in procedure • ROBUST Series with PEEK cage • Provides limiting speed over 2.5 Mil. dm* n • Machine Tools Nominal Bore Diameter Bearing Type Symbol Dimension Symbol