Pictures Of Curtain Tieback What Kind Of Can I Use To Be Able To Nail Through Metal (trying To Hang Curtains And Pictures)?

What kind of can I use to be able to nail through metal (trying to hang curtains and pictures)? - pictures of curtain tieback

We have a new house a year and I arrived at the point where I can hang more pictures. I like hanging curtains and pictures, but in certain areas of the wall can not be through the metal nail, because it is below the wall. The frame of the house is made of metal (the manufacturer told us that before the purchase of the house).

Is not there some sort of device that is me, where can I buy, and I can polish can say? There is also a tool or device that allowed me to metal nail?