In what situation is it best to set countersink depth?

Setting countersink depth is best done in practice holes because this initial step allows for precision and adjustments before moving on to the final assembly stages. By practicing on holes that mimic the intended application, mechanics can determine the ideal depth needed to accommodate rivets or screws securely while ensuring the required flush finish with the material surface.

This practice session allows for testing different depths and angles, minimizing the risk of errors in the final application. Once the correct countersink depth is established through practice holes, this knowledge can be applied to actual assemblies, ensuring quality and consistency in the finished product. The ability to refine techniques in a controlled environment, without impacting the final assembly, leads to better outcomes in actual production scenarios.