How to tell if a piece has alreadt been heat treated?

[hollowhandle]

I recently was given a blade and it looks finished. How can I tell if it has already been heat treated.
Thanks

 

[Crayola]

run a file over the edge. A dul file will skate over the edge. A brand spanking new file will maybe bite a bit, but still skate along.

 

[Ripper]

Hi,
If it already has an edge on it, I'd try the brass rod test. Here's a link to more info:
http://www.bladeforums.com/forums/showthread.php?s=&threadid=108068&highlight=brass+rod
Regards,Greg