What is the difference between unf and unc?

"UNF" stands for "Unified National Fine" thread, while "UNC" stands for "Unified National Coarse" thread. The primary difference between the two lies in their thread pitch: UNF has a finer thread pitch, meaning there are more threads per inch, which allows for better grip and holding power in certain applications. Conversely, UNC has a coarser thread pitch, making it easier to assemble and disassemble, and is generally more robust for heavy loads.