You should be using the thin shiney metal thats in between the rubber of the blade, try and use an original blade as the after market ones in your country may be sub standard but thats only an idea, you shouldnt heat them nor should you need to i think this was mentioned on one of your previous posts.
You should be able to hold one end in some pliers and bend the other side over with your fingers, if you are holding both sides with pliers and holding the pliers touching then i would imagine you are stretching the material instead of bending it.
Show us a pic f the material, how your bending it and a finished wrench for more advice
