I've been on AS for almost ten years now. In that time I've read where a couple guys have said they cut so much firewood they wore out 2 or 3 bars in a year, almost like they were bragging. I just kind of shook my head. I've got big saws with bars on them that are over 40 years old with no sign of roll over on the rails. These were saws of the 70's that put in 20 years of commercial use with my Dad, then another 20 years of use with me cutting firewood and milling. Then last week I pulled the 36" bar off my 660 to put the 25" on for firewood duty. As I lifted the chain off the bar I could feel a lip on the rails. I guess the 660 is about 4 years old now, and doesn't get near the use my old ones did. Does anyone know, or think, that they used harder steel in the bars way back when? Joe.