... rods including grade C, K, D, KD, HL, HY and KH. Among them, grade C, K, D sucker rods are designed ... and HY according to SY/T5029-2006 standard, and grade KH according to company's specification. Grade C sucker rod is ... big-pump capacity oil-well. And grade K, KD and KH sucker rod are made from fine Cr-Ni-Mo alloy ...