Why loosening torque is lesser than the tightening torque for bolts/screws
In my experience, loosening torque is not always less than tightening torque, sometimes it is more. I can think of two reasons for it to me more. Sometimes there is molecular binding of the metals if abrasion occurs during tightening. Also some imperfections in the geometry of the nut and mating surface could cause the nut and surfaced to engage like a ratchet.