In HC50 Hydraulic Rock Drill (or Hydraulic Drifter) systems, the Thrust washer 86582855 is a “silent load-bearer” for rotating components—it’s installed between parts like the transmission gear and shaft, absorbing axial thrust generated during high-torque drilling (up to 500 N・m for HC50) and preventing direct metal-to-metal contact. This not only reduces friction (lowering energy loss by 8-12%) but also protects expensive components from premature wear. With over a decade in mining equipment maintenance, I’ve seen generic thrust washers fail drastically: most use low-hardness steel (HRC < 30) that wears down to thin sheets in 400-500 hours, leading to shaft misalignment, noisy operation, and even gear damage. These failures cost mines $2,500+ in repairs and 2 days of unplanned downtime—major hits to productivity.