Final Answer:
Tightening torque can decrease over time from factors such as settling, relaxation, or elastic deformation.
Step-by-step explanation:
The tightening torque applied to fasteners can decrease over time due to several factors. Settlement of the materials being fastened, relaxation of the materials or the fastener itself, and elastic deformation are common reasons for a decrease in torque. Settlement occurs as materials compress or adjust under the applied load, leading to a reduction in the initial torque. Relaxation refers to the gradual loss of tension in the fastener over time, and elastic deformation involves the materials undergoing changes in shape or structure, impacting the torque applied during the tightening process.
These factors are particularly relevant in applications where maintaining a consistent torque is crucial for the integrity and safety of the assembly. Regular monitoring and re-tightening may be necessary to ensure that the fasteners maintain the required torque levels for optimal performance and reliability. In industrial settings or critical installations, understanding and addressing the factors contributing to torque loss over time are essential for maintaining the structural integrity of assembled components.