1.
Definition of being strong,
rude and super brave, and referencing the male balls because the harder they are, the manlier the
man is.
2. Having your balls masked in steel, or having your balls made of steel.
1. Duke Nukem: I've got balls of Steel.
2.
Dude: Hey you know what the "Balls of Steel" pill does in TBoI?
Other dude: i think it adds 2 soul hearts
3. Boy: I'll be asking the menacingly looking
man's daughter out.
Other boy:
Man, you've got Balls of Steel!