... welding machine drill collars, the most complete processing equipment and testing equipment.The company was founded in 2005, and ... rods including grade C, K, D, KD, HL, HY and KH. Among them, grade C, K, D ... -corrosion environment oil-well widely. Grade HL and HY sucker rods are super-high strength sucker rod, ... is capable to reach 966~1195Mpa. Grade HL, HY sucker rods are suitable for the deep oil- ...