API 11B sucker rod is a long, slender, high-strength steel rod used in rod-pumping systems for oil and gas production. It forms a continuous rod string that connects the surface pumping unit to the downhole pump, transmitting reciprocating motion to lift crude oil and production fluids from the wellbore to the surface. 

Manufactured in accordance with API Specification 11B, sucker rods are designed to withstand high tensile loads, cyclic fatigue, and harsh downhole conditions such as corrosion, pressure, and temperature variations. 

The rods are precision-machined with threaded ends and connected by couplings to create the required length for different well depths. Available in multiple grades and sizes, API 11B sucker rods provide reliable performance, long service life, and efficient power transmission, making them an essential component in conventional oil well artificial lift systems.