I checked the unloaded weight of the squat machine I have been using. It says 52lbs.
I now know that my squats have been 1 set each of 5 reps X 142, 232, 282. Not bad for a 140 lb guy.
Also bench press with olympic bar is 1 x 135, 155, 175
The low rep method is working well for me...
I sometimes add a set of Pullups - 10 reps, and assorted other things like dumbbell shrugs with 45 each, or tricep presses after the bench press routine. Keeps it interesting.