... can provide sucker rods including grade C, K, D, KD, HL, HY and KH. Among them, grade C, ... manufactured according to the API Spec 11 B, grade KD, HL and HY according to SY/T5029-2006 standard ... big-pump capacity oil-well. And grade K, KD and KH sucker rod are made from fine Cr ... steel containing different amount of Ni. They possess more powerful anti-corrosion function. The products are suitable for ...