It really depends on how frequently each part is trained. I feel like I can fry my chest with 10 sets (5 flat, 4 incline, 1 dumbell or dips, not including warmups), but I train each part 2-3 times per week. A good way to measure volume is how many sets per week. If sets were never taken to failure, even 30 sets wouldn't overtrain me. I am always on the edge of overtraining, but that is how I progress.