How much damage can be inflicted with a punch from brass knuckles?

I know a punch to the face could break their akull and kill them but what about a punch with brass knuckles to the gut or ribs?|||You can kill someone with a single punch, even without brass knuckles, if you know what you are doing. You can indeed break ribs and damage internal organs, with or without the brass knuckles.|||you could kill the person.|||Broken bones.|||cyanne is right plus they are illegal in all States.