1-) C# DEVEXPRESS RMOS - chartControl1  ViewType.Bar çubuğunu kalınlaştırma

series4 = new Series("HAT " + item["hatlar_sira"].ToString() + " de " + item["kacTane"].ToString() + " Tane Hata", ViewType.Bar);

SideBySideBarSeriesView view = series4.View as SideBySideBarSeriesView;

                    view.Border.Visibility = DevExpress.Utils.DefaultBoolean.True;

                    view.BarWidth = 4;

kaynak : https://docs.devexpress.com/CoreLibraries/DevExpress.XtraCharts.BarSeriesView.BarWidth