No Steel type can be poisoned, unless the attacker has Corrosion. Until Generation 6 it also resisted Ghost and Dark, and it lost both when the Fairy type arrived.

Its attacks are super effective against Ice, Rock and Fairy, and not very effective against Fire, Water, Electric and Steel. On defence it takes double damage from Fire, Fighting and Ground, and resists ten types: Normal, Grass, Ice, Flying, Psychic, Bug, Rock, Dragon, Steel and Fairy. It is immune to Poison. There are 65 Steel-type species, 10 of them pure Steel; the most common pairings are Steel/Psychic (8), Steel/Rock (7) and Steel/Fairy (6). It has 38 moves: 24 physical, 7 special and 7 status.

Steel-type Pokémon 65

Steel-type Mega Evolutions and regional forms 22