What do all grenade bodies have in common?

All grenade bodies are designed to be hollow and hold a filler, which is typically an explosive material or some type of composite charge. This characteristic is essential because the filler is what allows the grenade to function as a weapon. The hollow structure enables the explosive charge to be contained and ensures that when the grenade detonates, it can effectively create fragmentation or a blast effect, depending on its design.

The design of grenade bodies must allow for safe and effective transportation and activation while ensuring that the filler material is secure until detonation. Thus, the commonality of the hollow design is central to all types of grenades, regardless of their specific function or the type of filler they contain.

The other alternatives do not hold true universally across all grenade types. While some grenades may have a timing fuse, not all do, as some utilize impact fuses instead. The claim that all grenade bodies are made of metal is also inaccurate since some may use composite materials or other substances for weight reduction or safety. Furthermore, the idea that all grenades are filled with gas is incorrect, as most contain solid explosive materials rather than a gaseous filler.