As Charlie Chaplin figured out during his brief assembly-line career depicted in the 1936 film Modern Times, tightening bolts all day can be a real pain. Lucky for Charlie, and for any one of us working on a mechanical project, there’s good news at the other end of the wrench: Loosening a bolt takes less torque than you originally put into tightening it.(…)
via Why it Takes Less Torque to Loosen a Bolt Than to Tighten It.