not only are couplings and line shafts required to transmit torque from driving to driven elements but they must also compensate for misalignment between two shafts. Precision couplings ensure a backlash and maintenance free transmission of torque throughout their operations unlike standard couplings. This precision coupling is so precise because of the tight tolerances and dimensional accuracy measured in hundredths of a millimeter of the individual precision coupling components. Despite the large variety, precision couplings can be divided into two main groups: torsionally rigid couplings and vibration damping couplings. The torsionally rigid couplings are often used in the x-y axis of machine tools whereas vibration damping couplings are mainly used in spindle motors or conveyor units.

torsional rigidity describes the rigidity of a coupling when it is subjected to a torsional load. If the torque is to high and the maximum torsional value of the coupling is exceeded, the coupling will no longer be strong enough to transmit the acting rotational force, the unit "torsional rigidity" (nm/rad) reflects this relation. Each coupling has a permissible angle of twist with most rigid couplings having a maximum angle of twist of less than 0.05 degrees, and vibration damping coupling having a maximum angle of twist of less than 5 degrees. If the admissible angle of twist is not exceeded, the coupling will have an infinite life.

not only are couplings and line shafts required to transmit torque from driving to driven elements but they must also compensate for misalignment between two shafts. Precision couplings ensure a backlash and maintenance free transmission of torque throughout their operations unlike standard couplings. This precision coupling is so precise because of the tight tolerances and dimensional accuracy measured in hundredths of a millimeter of the individual precision coupling components. Despite the large variety, precision couplings can be divided into two main groups: torsionally rigid couplings and vibration damping couplings. The torsionally rigid couplings are often used in the x-y axis of machine tools whereas vibration damping couplings are mainly used in spindle motors or conveyor units.

torsional rigidity describes the rigidity of a coupling when it is subjected to a torsional load. If the torque is to high and the maximum torsional value of the coupling is exceeded, the coupling will no longer be strong enough to transmit the acting rotational force, the unit "torsional rigidity" (nm/rad) reflects this relation. Each coupling has a permissible angle of twist with most rigid couplings having a maximum angle of twist of less than 0.05 degrees, and vibration damping coupling having a maximum angle of twist of less than 5 degrees. If the admissible angle of twist is not exceeded, the coupling will have an infinite life.