In HC50 Hydraulic Rock Drill (or Hydraulic Drifter) operations, the Spline shank 101148259 is the “power bridge” between the drill’s transmission system and the shank—it’s responsible for transferring high torque (critical for breaking hard rock) while withstanding the vibration and impact of continuous drilling. With over a decade in mining equipment maintenance, I’ve seen generic spline shanks fail repeatedly: their spline teeth are often made of low-strength steel that wears down or strips in just 400-500 hours. This leads to uneven torque transfer, reduced drilling speed, and even damage to the drill’s main transmission gear—costing mines $6,000+ in repairs and 2-3 days of unplanned downtime.