Rod End Bearings, also known as a heim joint (N. America) or rose joint (U.K. and elsewhere), are a mechanical articulating joint. Rod End Bearings are used on the ends of cylinders, linkages, rods, and shafts to take up misalignment between connected parts. They consist of a spherically-shaped inner ring and a cylindrical bore for mounting on a shaft. Rod End bearings attach to rods and shafts via a male stud with external threads or a female housing with internal threads. Right-handed threads tighten in a clockwise direction and are the most commonly used type of thread. Left-handed threads tighten in a counterclockwise direction and must match the mating part.
Rod end bearings differ in terms of dimensional specifications and special features. Dimensional specifications include design units, bore diameter, major diameter, bearing thickness, housing diameter, overall length, and thread length. English design units include inches (in) and fractions of an inch. Metric design units include millimeters (mm) and centimeters (cm). Bore diameter is the inner diameter (ID) of the bearing bore. Major diameter is the nominal diameter to the top of the threads. Bearing thickness is the length through the bore. Housing diameter is the outside diameter (OD) of the bearing housing. Overall length is the distance from the top of the housing to the end of the shank. In terms of special features, some rod end bearings are self-lubricating or include a lubrication port. Others are corrosion-resistant or equipped with PTFE seals.