Definition(s)
Rod (sucker rod)
A length of steel, aluminum, fiberglass, or other suitable material, a number of which are screwed together to make up the mechanical link (rod string) from the surface pumping unit to the pump in the well.
Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global Standards