True or False: It is acceptable to have marks on or around the heads of rivets during visual inspection.

During a visual inspection of rivets, the presence of marks or defects on or around the heads of rivets is generally considered unacceptable. Rivets are critical fasteners that provide structural integrity to aerospace assemblies, and any imperfections or markings can indicate issues such as improper installation, corrosion, or fatigue.

Visual inspections are conducted based on strict standards to ensure safety and reliability. If there are marks around the heads, it may suggest that the rivets have experienced undue stress or potential damage that could compromise their performance. The determination of a rivet's condition should adhere to rigorous industry guidelines, which typically specify that rivet heads should be free from any unnecessary markings to ensure reliable fastening.

Such standards ensure that all assembled components maintain the necessary structural integrity required for flight safety, which is paramount in aerospace applications. Therefore, for all rivet types and under typical inspection standards, finding any marks or defects on rivet heads would warrant rejection during an inspection.