Which of the following is an example of permanent fixings?

Welding is considered an example of permanent fixings because it involves the process of joining two materials, typically metals, through the application of heat and pressure, which causes the materials to fuse together. This creates a strong and long-lasting bond that is not intended to be disassembled without damaging the components being joined. Once welded, the joined parts cannot be easily separated without cutting or destroying the welded area, which is a key characteristic of a permanent fixing.

In contrast, nuts and bolts can be removed and replaced, making them non-permanent fasteners. Similarly, snap closures and clips are designed for easy attachment and detachment, allowing for flexibility and convenience in usage, but they do not provide the permanence associated with welding. Thus, welding stands out as the definitive example of a permanent fixing due to the irreversible nature of the bond created during the process.