Onix does not evolve into Steelix by leveling up but by trading it with another trainer holding Metal Coat.
You must ask for the Pokémon back or else you'll lose it and will not count on your Pokédex.
Trade onix while it is holding metal coat
Onix does not evolve by level. It can evolve by being traded while holding metal coat.
you have to trade it when held with a metal coat.
Level: Onix Evolves By Trading.
there is no level for onix to evolve it will evolve if u trade it to another game make sure it holds a metal coat or it will not evolve
level it up
You have to trade him
In Pokemon, Onix does not evolve at a specific level. The only way that Onix can evolve into Steelix is by trading it to someone while it is holding a metal coat.
onix has to be traded and be holding metal coat
level 50
Onix doesn't evolve through leveling. But, make him hold a Steel Coat, and he will evolve into a Steelix!
Level up your Groudch