This sets the default value for the field of XY Step Size under the Cut Control tab. To the right of this setting, you can choose Constant or Cutter Radius from the pull-down. The Cutter Radius option multiplies the Side Step Size by the cutter radius to calculate the default XY Step. The Constant option sets the default XY Step to the Side Step Size. To see the results, you must open a new operation dialog and change the tool.