Originally Posted by home brew
Heat is ALWAYS a no-no! NEVER heat and I-beam axle! Most of those things are a malleable iron casting and if you heat it anywhere near hot enough to bend it the structure changes in the iron itself and it will become weak and brittle in the heated area. Malleable iron casting are almost as strong as steel until you heat them then they are changed into common Grey iron and cooling them slowly will not help this at all, once heated that hot they are for all practical purposes scrap. Even a steel casting could be weakened from heating and maintaining the structural integrity is a fairly complicated procedure that can not be duplicated by simply letting it cool slowly. NEVER allow anyone to heat an axle on your truck!