Hi, what level does onix evolve into steelix?

Onix evolves into Steelix, just not at a certain level . You must first equip Onix with a Steel Coat which you get from rescuing the guy's grandaughter on the SS Ship after you beat the Elite Four. Then trade the Onix with Steel Coat to another version (Gold or Silver) and it will evolve into a Steelix then trade it back and voila. You have a Steelix.

Hey!
In order for onix to evolve into Steelix, you must get the metal coat which is on the ss aqua. You must find the old mans daughter, and then he will give it to you. Make onix hold it and trade. Hope that helps.

Onix evolves into Steelix when you trade and Onix to another Gameboy holding a 'Steel Coat'. I can't tell you how to get a Steel Coat, but I think you get one through the story anyway.

Trade an Onix while it's holding a Metal Coat.

Hey guys hey girls inorder of onix to evolve,you have to make your onix hold a metal coat that you get from the s.s.anne. Then, you must trade with a different version, and BOOM! Theres your steelix. ALRIGHT, HOPE THAT HELPS

go to the ss aqua in kanto. Then go rescue the little girl and then you will recieve a metal coat. After that give the metal coat to onix and trade. Hope i helped!

Frist capture a Onix then when you're in S.S.Anne(or Aqua)Find the Daughter of the man that hit in you and then give the Metal Coat you receive to Onix then trade with Pokemon:Red,Blue or Yellow

My Pokemon crystal in on my mobile phone...how can trade it>>>???

Its simple just go to ss aqua and get the metal coat. Then give the onix the metal coat and trade it with your friend. As onix is holding metal coat during the trade the onix will evolve into steelix. Then trade it again with your friend and here it is, a powerful steelix. Now enjoy