Spindle Ball Bearings
Characteristics: High accuracy (P4/ABEC 7); 15° to 25° contact angle; universal pairing (DB, DF, DT).
Advantages: Stiffness 2x standard angular contact bearings (due to optimized ball size and rib contact). Lifetime 8000h at 20,000 rpm in CNC spindles vs. 3000h for standard.
Technical Ceiling: Axial runout <2 µm; thermal growth 0.3 µm/°C; limiting speed (oil jet) = 1.5M DN; dynamic stiffness >100 N/µm.
Caution: Standard bearings lack the preload control – substituting causes chatter and poor surface finish. Spindle bearings require precise locknut torque (e.g., 8 Nm for 7012 size). Never hammer fit.
