Material:20CrMnTi, Our company is specialized in producing series of track pin and track bush for Hitachi, caterpillar, Daewoo doosan, komatsu, kobelco, Hyundai, Mitsubishi, Samsung Volvo, sumitomo, kato, etc. Heat treatment: high frequency,hardness HRC is 52--58.. The products made per customers' requirments.Please feel free to contact with us If you are interesting in them!! track bushing