Trying to freehand a spiral on a hot bar was my worst idea yet.
In my experience, when you try to twist steel by eye, it never comes out even. I was making a fireplace poker and wanted a fancy spiral handle. I heated the bar and started turning, but one section cooled faster than the rest. The twist kinked and left a weak spot that cracked later. Your mileage may vary, but take this with a grain of salt: if you're not using a jig or marks, you're asking for trouble. Now I always scribe lines before twisting, no matter how simple it seems. It might add time, but it saves the piece from becoming scrap.