It was narrated from Jabir bin Samurah that: a man killed himself with an arrowhead and the Messenger of Allah said: As for me, I will not pray for him.
It was narrated from Abu Hurairah that the Prophet said: Whoever throws himself, he will be in the Fire of Hell, throwing himself down forever and ever. And whoever kills himself with a piece of iron - then I missed something ( one of the narrators) Khalid said- will have his piece of iron in his hand, stabbing himself in the stomach in the Fire of Hell, forever and ever.