ofcourse i realise strength is gained in width as well... but in the automotive example i used the width of the wheel stud is not changed... only the length... there is an actual stated point where a stud has its maximum strength, this is when there is a length equal to or greater than the width (size) of the stud pertruding past the backside of the nut threaded onto it... i believe it to be a situation of leverage...

and since its much more potentialy problematic to file open your trackends to recieve an oversized axle than it is to install a longer axle of the traditional size... it seems to me like length would be the better alternative then width
-pete