Axis.MajorTickMark (PowerPoint)

Returns or sets the type of major tick mark for the specified axis. Possible return values are xlTickMarkCross - Crosses the axis, xlTickMarkInside - Inside the axis, xlTickMarkNone - No mark, xlTickMarkOutside - Outside the axis.

MajorTickMark can be set to one of the following xlTickMark constants:

ActivePresentation.Slides(1).Shapes(1).Chart.Axes(1).MajorTickMark = xlTickMarkCross