I need to mate the gusset plate to the repad.  The repad will eventually be added to the side of a tank, so I have created the parts with the appropriate radii.  On the gusset plate I made an extrude cut with the radius, thinking that it would mate up with the repad's outside radius.  However I can not get the Coincident or Concentric mate to work.  Is there an easier way or something I am missing?  The assembly file shows that I need the gusset plate to be perpendicular to the repad as well.

-Craig