Rusted Metal?

Finally got 3U on the 3DS and I have been playing it for the past 5 days (hooray).
So I got an item called "rusted metal" (I think that is how it is called, I'm playing it with the spanish language so...) that i got from the fishermen (don't know how they are called in english either). So can I make the rusted weapons from them or are they just an useless item for resources?

It's rusted fragment if i'm not mistaken. You use it for making special kind of armor called Artian. Which is very helpful especially legs for blademaster.

But i think you should ask this question in Q&A thread rather than making new topic:

https://mhwiki.forumotion.net/t9139-monster-hunter-u-qa-thread