I live in a metal home.  Picture hanging, and hanging anything in general, was a nightmare.  I bought several magnetic hooks in the weight they were designed for.  They didn't come loose, but they would slide down the wall.  Some of my framed pictures are rather heavy, and I need a way to secure them.  I was able to do the job with this 100 lb. magnet.  I intend to buy more, and thus, enjoy my artwork.