HOME and how to join Forum Open Area General Scott topics whats the purpose of dual hex nuts Re: Re: whats the purpose of dual hex nuts

#12682
BRIAN MARSHALL
Participant

According to my son, recently retired RAF Chief Technician (Airframe), the idea behind these nuts was that you tightened them into place using the smaller of the two hexagons, and loosened them using the larger hexagon, the idea being that you were less likely to overtighten them when using a smaller, shorter spanner. Bear in mind that this was a half-baked theory for the days when nobody out ‘in the field’ had heard of a torque wrench ! The idea fails dismally of course because the two different hexagons were probably on opposite ends of the same spanner, so exactly the same amount of leverage could be applied. When in use on an aircraft there was also a slight weight-saving consideration, and the cost of making them would be of little consideration. Many fasteners on an aircraft are in very awkward to access positions, and no doubt having two different hexagons also offered the opportunity to use different tool sizes when in a tight corner…
Now you know.
Brian