It depends on the design of the hanger and the type of rock. Often it will be a 3/4" or 5/8" expansion bolt

Expansion bolt method

Just about in the dead center of the firewall. It has one small tube and one slightly bigger tube connected to it. You will also see and Allen bolt in the middle of it.

The loud noise is called 'thunder' or 'a thunder clap'. The sudden increase in pressure and temperature from lightning produces rapid expansion of the air surrounding and within a bolt of lightning. In turn, this expansion of air creates a sonic shock wave which produces the sound of thunder.

The expansion in the number of conquered people did not affect Rome's expansion because it was the product of her expansion.