This is also informative:
The article on bending the bar was really interesting. i always wondered why there aren’t bailouts on racks that allow the plates to touch first on the dump. I thought it was interesting how they said it?s a myth that leaving plates on the bar will bend it.
This article goes into it a bit further
I though this analogy was interesting: ``you can take a 100 pound woman. Is she stepped on your back barefoot, it would probably feel good (depending on the woman!).
However, if she were wearing spiked high heel shoes, it would probably feel like hell. The reason for this is that at the end of a small area she does not weigh 100 pounds - she might as well weigh 2,000 pounds.
This is a very important factor when we talk about how bars bend because when a bar falls and hits a small area, like pins through a power rack, it might only have 400 pounds on the bar but if it drops 3 feet and hits that pin, perhaps the blow is equal to 5,000 or 10,000 pounds. This is the way almost all bars are bent.’’