Almost every kitchen has one of those "old timey" potato mashers which Gramma used in the days before instant mashed or electric mixers. I still have mine and a few years ago, I broke the handle off yet another hamburger flipper. It was beginning to happen with alarming regularity.
I got out the potato masher and smushed my hamburgers down and used the edge to flip them over. There is no pressure on the handle since you are pushing straight down. They are just about the right size for a burger.
I use mine for this all the time, and haven't broken a spatula since I started using the potato masher for this purpose.