Ceramic bearing
6904 Ceramic Ball Bearing 20×37×9 mm – Waterproof Zirconia for High-Speed Applications
Extend bearing life and eliminate unplanned downtime in high-speed, moisture-prone environments — the 6904 ceramic ball bearing delivers unmatched rotational stability where steel bearings fatigue or corrode. Engineered with full zirconia balls and hybrid 20×37×9 mm geometry for true P4 precision — critical for wind turbine pitch systems and mining conveyor idlers Waterproof by design: non-porous ceramic elements resist electrolytic corrosion even under continuous washdown or salt-laden air Runs cooler at >25,000 rpm thanks to ultra-low thermal expansion (α ≈ 10.5 × 10⁻⁶/K) — a detail that separates field-proven zirconia from generic “ceramic-coated” imitations Backed by SKF-compatible engineering support: our in-house P4 application team validates fit, preload, and thermal clearance before shipment