Breaker Bushing Set kit of metal sleeves we fit between the hammer housing and piston or tool bit to reduce friction and wear. We press these bushings into the hammer’s bore so the moving parts slide smoothly when oil pressure drives the piston. Made from hardened steel or bronze, they protect the bigger parts from grinding on each other. When we service the breaker, we swap old bushings for fresh ones using a press or hammer. Good bushings make the hammer last longer and hit harder.