Thread length needs to be Specified in mm when drawing is in inches

Yesterday, I needed to insert a length of 1/4-28 UNF thread into a model.  I selected the thread and then the desired length from the dropdown.  The thread inserted was far shorter than what I selected.  I figured out that I even though my drawing was using inches, the thread length had to be specified in mm.  Not hard to do, but an extra step.  I assume there is a setting somewhere to alter this behavior.  Can anyone point me in the right direction?