How much clamping force do I really need?

For most woodworking glue-ups, 600–1,000 lbs of force per clamp is more than sufficient, and many reviewers note that over-clamping squeezes out too much glue. Heavy-duty parallel clamps rated at 1,000–2,200 lbs are aimed at large panel and cabinet work; trigger and quick clamps in the 150–600 lb range cover the bulk of light assembly tasks.