In HC50 Hydraulic Rock Drill (or Hydraulic Drifter) operations, the Shank sto 86334125 is a vital “shock absorber” for the shank—this component directly bears the high-impact force from the shank during drilling (up to several thousand Newtons per impact) and prevents the force from damaging delicate internal parts like the cylinder or valve. With over a decade in mining equipment maintenance, I’ve seen generic shank stos fail catastrophically: most use low-hardness metal that wears down in just 200-300 hours, leading to excessive shank movement, uneven drilling depth, and even cracks in the drill’s housing. These failures cost mines $5,000+ in repairs and 2-3 days of unplanned downtime.