How frequently should countersink depth be checked during assembly?

Countersink depth should be checked every 10-20 holes during assembly to ensure uniformity and adherence to specifications. This frequency strikes a balance between maintaining quality control and efficiency in the assembly process. Regular checking allows mechanics to identify and correct any variations in depth that may occur due to tool wear or operator technique. Checking too infrequently—like every 50 holes or only at the end of the process—could lead to cumulative errors, affecting the fit of fasteners and compromising the integrity of the assembly. Conversely, checking every 5 holes may interrupt workflow unnecessarily without providing significant added value in terms of quality assurance. Thus, inspecting countersink depth every 10-20 holes is the optimal practice for maintaining precision in aerospace assembly work.