Final answer:
Rust on a fastener can reduce its load-bearing capacity, affecting the ability to maintain the proper clamping force, and may lead to mechanical failure.
Step-by-step explanation:
Using a fastener with rust on it can indeed affect the clamping force that the fastener can apply. Rust is the result of the oxidation of iron, which can weaken the fastener material and therefore reduce its load-bearing capacity. In a situation where precise clamping force is critical, a rusted fastener may not provide the required tension, thus compromising the integrity of the connection. This can lead to an inability to apply sufficient torque, and an increased likelihood that the fastener will fail under normal conditions. The creation of rust can also lead to an increase in friction which can affect the torque-tension relationship, making it harder to predict the necessary torque to achieve the desired clamping force.