Norris sinker bars provide concentrated weight above
the pump to help keep the rod string straight and in
tension, which reduces buckling of the sucker rods or
the pump plunger. Norris sinker bars are made from hot
rolled carbon manganese steel bar stock. Sinker bars
are surface turned and have API double sucker rod pins,
shoulders, and wrench flats on both ends. One end has
a reduced section for elevator seating and lifting.
The current edition of API Specification
11B recognizes two grades of sinker bars:
API Grade 1 - Carbon (AISI 10XX) and
API Grade 2 - Alloy (Optional with manufacturer)
Below are the material types offerd by Norris relative
to the two recognized API grades.
API Grade Material Type Mechanical Strength
Properties
