You can find them as a swarm in fuego ironworks. To know what is the (swarm of the day),you need to go to sandgem town. Go to Dawn/Lucas's house. There is a little girl inside. Talk to her and she will tell where is the swarm today.
The only way to get Magneton is to evolve a Magnemite.
Swarm occasionally, in front of Fuego Ironworks.
You can find a Magnemite in Pokémon Diamond at a Swarm in Fuego Ironworks with a Rarity of 40%.
I think you find it in fuego ironworks near floaroma town (you will need to have a Pokemon that knows surf) use poke-radar and do long chain until you find a magnemite.
talk to dawns sister everyday until she say where magnemite is
In Pokemon Diamond and Pearl you need the National Pokedex to get Magnemite. In Pokemon Platinum you don't need the National Pokedex to get Magnemite.
You can find it on certain electrical Pokemon such as plusle, minun, magnemite, etc. You can find it on certain electrical Pokemon such as plusle, minun, magnemite, etc. You can find it on certain electrical Pokemon such as plusle, minun, magnemite, etc.
Sometimes they're in a swarm at Fuego Ironworks (ask dawn's sister after you beat the elite four)
The occasional swarm makes Magnemite available in front of Fuego Ironworks for Diamond. It can be regularly found there or other places in Platinum, or traded from Heartgold and Soulsilver.
It is in Fuego Ironworks when there is a Swarm.
You can make Magnemite appear in Fuego Ironworks as a Swarm after you obtain the National Pokedex from seeing every Pokemon in the Sinnoh Pokedex. To know if Magnemite has appeared talk to your rival's sister in Sandgem Town. If Magnemite hasn't appeared try again the next day as Pokemon Swarms change every day.
Magnemite is found in the Power Plant.