They can be very tight, the spec is a minimum torque, you then have to tighten it further to get a split pin hole to line up,how far varies. That is the explanation for one being tighter than the other.
I have a twisted Halfords 3 foot 3/4 inch breaker bar which got that way when I jumped on the 6 foot piece of Laser dinghy mast attached to it when I got one of the nuts to undo. It clearly states on the breaker bar 'do not use extensions'.... The nut undid ok and I could still use the breaker bar to do up the nut again. Not quite so tight.
