What causes toilet tank bolts to get stuck?

Over the course of time, the toilet tank bolts that attach the tank assembly to the toilet bowl may become stuck. If the tank needs to be removed for any reason, this rusty condition can make it difficult to do so. Because the bathroom is a moist environment, there is a risk of rust accumulating on any metal parts of the toilet. This rust can cause the toilet tank bolts to become extremely difficult to turn. In addition to the possibility of rust, a buildup of dirt could form on the bolts and cause them to get stuck. Tapping on the end of a wrench attached to the bolts with a hammer will usually loosen them enough to be removed.