When I use alt+S with whole chest each paralel face has different size. If I use extrude one by one I can get same size for each face. Why? I can't get same measurement of each paralel face using alt+S
Did you look at the other questions regarding ALT+S like:
https://cgcookie.com/questions/12272-alt-s-scaling-question ?
I don't know exactly what you mean, but it sounds like it could be the above-mentioned issue.