Creeping

Creeping is a time-dependent, plastic, and irreversible deformation that occurs during the relaxation phase of a bolted joint under constant stress as a result of dislocation movements in the material. It occurs under long-term loading, particularly when the time-dependent strength or fatigue strength is exceeded. In bolted joints, creeping leads to a loss of preload over time.

Creep refers to the time-dependent, plastic, and irreversible deformation of materials under constant mechanical stress during the loosening phase of a bolted joint. This phenomenon is caused by the gradual migration of dislocations in the crystal lattice, resulting in a slow change in length. This behavior typically occurs under sustained stress over extended periods of time. Creeping is promoted when the yield strength under static loading or the fatigue strength under dynamic loading is exceeded. In bolted joints, such effects lead over the long term—usually after months or years—to a reduction in the preload force and potential loss of function.

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Creeping

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Torque Recommendations

Residual Spring Characteristics

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