You may have to reword that question. But I will answer this question assuming that you mean "What are steel type's weakness in Pokemon?". Fire, fighting, and ground.
Dragon, Ice and Fairy-type moves.
Fire-type Pokemon are weak against Water, Rock, and Ground-type attacks.
Steel type Pokemon are weak against Fire, Fighting, and Ground type attacks
Steelix is a good Steel type Pokemon. It is also a Ground type, too.
I think the best steel type Pokemon is probably dialga.
water Pokemon and ground, their stong agaisnt insect grass and steel
Klink is a Steel type pokemon.
Dragon, Ice and Fairy-type moves.
Fire-type Pokemon are weak against Water, Rock, and Ground-type attacks.
Steel type Pokemon are weak against Fire, Fighting, and Ground type attacks
Steelix is a good Steel type Pokemon. It is also a Ground type, too.
I think the best steel type Pokemon is probably dialga.
Steel type Pokemon are weak to Fire, Ground, and Fighting, so those types of Pokemon will do well.
Registeel is a Steel type pokemon.
Klang is a Steel type pokemon.
A fire and a fighting type Pokemon is good against steel.
Ligtning type moves, and grass type moves are super effective against water.