... drilling, rotary drilling, trenching, tunneling, mining etc, aslo casing bits and cutters for shield machine.Round cutter Parts No.as ... B47k17H, B47k19H, B47k22H,Flat cutter Parts No. as BFZ80, BFZ70,Bucket teeth T25series and holder,T18 series and holder,Holders parts ... Steel Body, made by material 40Cr or 42CrMo, heat treatment with 40-44HRC hardness, has high toughness and wearable character. ...