Electric and Steel types: weaknesses, resistances and Pokémon
Electric and Steel Pokémon take quadruple damage from Ground moves, take double damage from Fire and Fighting moves, resist Flying, Steel, Normal, Grass, Electric, Ice, Psychic, Bug, Rock, Dragon and Fairy moves and are immune to Poison moves.
With 12 resistances and immunities against 3 weaknesses, it is a very solid defensive combination.
Electric moves are super effective against Water and Flying and not very effective against Grass, Electric and Dragon. Steel moves are super effective against Ice, Rock and Fairy and not very effective against Fire, Water, Electric and Steel.
To beat these Pokémon, your best pick is Ground moves. Avoid Flying, Steel, Normal and Grass moves, which deal little or no damage.
There are 4 Pokémon with this combination, such as Magnemite, Magneton, Magnezone and Togedemaru.