Honestly, I used to be right there with @taylor668 thinking it was always the heat or the metal. Tbh, I fought a twisted piece for a whole afternoon once before my buddy pointed out my bench itself was out of level. Ngl, it makes a huge difference if your setup isn't square. A worn vise jaw would totally put a sneaky bend in the work before you even start twisting. Sometimes the simplest tool problem is the real one hiding in plain sight.