It is a crucial step and one that must NOT be left out in remanucturing any cylinder. Grinding, polishing or revitalization of the micro oiling grooves on any hydraulic cylinder shaft is a must. Any cylinder repair is not complete without this procedure. If funds OR time are not avail for engineered hard-chromed plating, what we do is weld in to fill any scratches, hand grind to near surface and blend in perfectly with our grinder and grinding skill procedure. Manual blending utilizing rotating disc's cause scalloping and s more damage than good. Several major road machinery companies will vouch for our quick and effective procedure. WE pioneered it !