The required column's width is automatically set to the Width property's value.
The Horizontal Scrolling is Disabled
Column widths are adjusted automatically, so that the total width of all columns matches the grid width. Changing the width of one column automatically changes the widths of other columns. To obtain the actual width of columns, use their GridColumn.ActualWidth property.
If you set the Width property only for one column, and there are other columns that don't have this property defined, the GridControl will set your required width value for this column and decrease the widths of columns where the width isn't set. However, if you set the Width for all columns, or if certain columns whose width is not defined already reached their GridColumn.MinWidth value, the GridControl will modify the width of all other columns in proportion to their defined Width, but will set it to a value not less than MinWidth.