Is it acceptable to use the open countersink to deepen the edge break if it exceeds the largest allowable tolerance?

When considering the question of whether it is acceptable to use an open countersink to deepen the edge break if it exceeds the largest allowable tolerance, the correct response is that it is not permissible. Using a countersink in this manner can compromise the integrity of the material and the assembly.

Deepening the edge break with an open countersink could potentially cause issues such as weakening the structure, leading to stress concentrations that might result in cracks or premature failure. Furthermore, it might interfere with the fit and function of fasteners or other components, which are critical in aerospace applications. Precision and adherence to tolerances are foundational in aerospace assembly, where safety and performance are paramount.

In practice, if edge break tolerances are exceeded, it is essential to address the issue through proper engineering procedures, including possible rework or consultation with engineering teams, rather than relying on a method that could exacerbate the problem. This maintains the integrity of the assembly and adheres to the stringent safety standards required in aerospace work.