Winform datagridview列的宽度不符合为其设置的宽度

I am setting the width of a WinForm datagridview column to 140 and I am checking the width and it's 100. The grid is wide enough to make all columns wider. Why isn't the column accepting the 140 value? Is there a setting which controls the max width?I am setting the width of a WinForm datagridvie