provides the industry requirements for sucker rods and some related sucker-rod lift equipment. The three main grades of API spec 11b steel rods follow:
Grade C rods that have minimum and maximum tensile strengths of 90,000 and 115,000 psi, respectively.
Grade K rods that have a minimum tensile strength of 90,000 psi and a maximum strength of 115,000 psi. These rods are made with 1.65 to 2.00% nickel and are, therefore, more expensive than Grade C rods, but may have improved corrosion-related properties.
Grade D rods that have a minimum tensile strength of 115,000 psi and a maximum strength of 140,000 psi. Three types of this grade are covered by Spec. 11B: plain-carbon, alloy, and special-alloy steels.