What’s the classification of sucker rod?

Sucker rods mainly has the following products: Ordinary sucker rod: C, D, K, KD grade sucker rod High-strength sucker rod: H grade, divided into three types: HY, HL, KHL Special sucker rod: hollow sucker rod Continuous sucker rod: steel rod Special sucker rod for PCP pump: taper thread sucker rod, plug-in sucker rod FRP sucker rod: fiber reinforced plastic sucker rod Flexible sucker rod: carbon fiber composite sucker rod, steel wire rope sucker rod Other types of sucker rods: electric heating sucker rods