I second this as standard practice in bike shops. A related question: I worked with someone who when he had a drop out that was very bent, often a intergrated der hanger, he would bend it then heat it up to a dull red then let it cool. He claimed that this counter acted the metal fatigue. This makes common sense to me, but I've never felt confident enough in this to charge a customer for it, but have done this on my own for non critical applications. Does this make sense? And if so are the more detailed specs of how to heat and cool the metal?