What fullform of UNC nut and bolt?

The full form of UNC nut and bolt is Unified National Coarse. It is a standard for screw threads used in the United States and Canada. UNC threads are characterized by their coarse pitch, which means that there are fewer threads per inch than on other types of threads. This makes UNC threads easier to tap and cut, and it also makes them more resistant to stripping. UNC nuts and bolts are commonly used in construction, automotive, and other industrial applications.