Met behulp van kwalitatief hoogwaardige bi-metalen koperen buizen; goed gesmeerd olierecyclusysteem; hooghardheid, slijtvast kruis legering drijvende afdichting & elastische rubber O-ring; Enhancement of wear resistance of rail surace by medium frequency quenching The axle is made of hich quality 45# steel which is enchanced the wear resistance by tempering and high frequency surface heat treatment.