The Roller Thrust Bearing 86676822 handles both radial and axial forces in HC25 Hydraulic Rock Drills, supporting rotating components like gears and shafts while minimizing friction. Generic roller thrust bearings use low-grade steel balls that deform within 500-600 hours, increasing rotational resistance and noise. This OEM bearing is manufactured from GCr15 high-carbon chromium steel, heat-treated to HRC 60-65 for high load capacity (40% higher than generic bearings). Its precision-ground rollers and raceways ensure smooth rotation with minimal friction, maintaining performance until mandatory replacement after 800 hours.