You need to turn off automatic labels and provide custom ones - for example:
NOrdinalScaleConfigurator scaleX = nChartControl1.Charts.Axis(StandardAxis.PrimaryX).ScaleConfigurator as NOrdinalScaleConfigurator;
scaleX.AutoLabels = false;
Please take a look at the All Examples \ Axes examples that show how to configure different types of axes as well as how to control labels, ticks etc. Let us know if you meet any problems.
Nevron Support Team