Hybrid Ceramic Ball Angular Contact Bearing 71910AC P4 High Speed 30000RPM Spindle Bearing

The 71910AC hybrid ceramic angular contact ball bearing combines a 25 degree AC contact angle with silicon nitride ceramic balls to control heat at elevated speed. A 50 mm bore, 72 mm outside diameter and 12 mm width keep it compact, while a basic dynamic load rating of 18.0 kN and static rating of 15.6 kN preserve carrying capacity. Ceramic balls are lighter and lower friction than steel, so centrifugal load on the raceway stays low and the bearing reaches 20000 RPM grease speed and 30000 RPM oil speed. The phenolic outer guide cage keeps ball motion stable and quiet throughout the speed range.

• Hybrid Ceramic Ball Set: Silicon nitride Si3N4 balls reduce weight and friction, lowering raceway temperature and permitting higher speed at a cooler running condition.
• 30000RPM Speed Ceiling: The 25 degree contact angle paired with ceramic balls allows 20000 RPM grease speed and 30000 RPM oil speed for high speed spindle heads.
• P4 Precision Class: Tight tolerance on bore and runout delivers low vibration, supporting fine surface finish on precision milling and grinding work.
• Thermal Stability: Lower friction and controlled preload limit thermal growth, keeping spindle geometry stable across long machining cycles.
• Durable Raceway: Through hardened bearing steel rings with an optimized groove geometry resist fatigue under combined axial and radial load.
• Long Service Interval: Reduced friction and smooth ball tracking extend grease life, cutting maintenance downtime for automated production lines.

The 71910AC is used in high speed spindles for CNC machining centers, grinding heads, dental and PCB drilling equipment, high frequency motors and test benches where low friction and temperature control are critical. Ceramic balls also resist electrical erosion, so the bearing suits motorized spindles exposed to inverter-driven shaft currents. It is a common upgrade path for machine shops that push spindle speed up without going to a fully ceramic design.

Each hybrid bearing ships in an anti-rust treated wrap with a foam cushion insert, packed in a labeled export carton. Ceramic balls are protected from impact during handling and transport. Incoming and outgoing inspection covers bore, runout, clearance, vibration and contact angle, and reports can be issued per batch. Custom preload, matching sets and grease selection are available to match OEM spindle specifications, with mixed pallet consolidation for overseas buyers.