I was able to squeeze the bathroom scales to ~65 lbs.
I don't think this was anything like an accurate measure of maximum clamping pressure, because the cam will only flex the spring arm to a hair short of 3/8" from rest. That went to the 65 lb. mark, but If I could get another purchase I think it would go more-not that you need much more to hold a tight glue joint until it sets.
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