A half inch of motor vehicle leaf spring steel (5160) that is differentially heat treated so the mass of the blade is left at spring temper is going to be extraordinarily hard to bend or break.
The old New England saying was "Don't strain. Get a bigger hammer." This is the "bigger hammer."
I do note that I have worked as an auto mechanic, carpenter, and in factory building demolition and never broke a single tool. I think there is a "feel" one can have - or not have - as to how much force to apply. I knew an old boy who bent 2" pinch bars regularly. He didn't get any more work done than the rest of us, but he was Hell on tools.