Why might one choose UNC threads over UNF threads?

Choosing UNC (Unified National Coarse) threads over UNF (Unified National Fine) threads is often based on the specific needs of the application. UNC threads, which have a larger pitch than UNF threads, are generally more effective in applications requiring higher strength due to their greater thread engagement. The larger thread profile is better at handling heavier loads without stripping because it offers a larger surface area for bolt tension, making them more suitable for rugged environments where strength is critical.

In contrast, UNF threads are designed for applications requiring precise adjustment and a tighter fit, but they can be more prone to stripping under high load conditions. Therefore, when the primary concern is to achieve a strong and secure fastening, particularly in high-stress situations, UNC threads would be the preferred choice.