OK....So let's really exam this trend of using a File to sharpen your blades. It sounds as though people actually believe in this method. I guess I need help, but I've tried the file thing and my Hustler blades, which are hardened to Rockwell 39, and it's just impossible. Also, I've kept an eye on this perception that the edge on your blade lasts longer on new blades, and it doesn't on my blades.
Pete
Pete