SMART datagrid v.1 > Classes > DisplayOptions
It specifies the default width of columns.
Defaults to 120.
    grid.setOptions({
        display: {
            defaultColumnWidth: 120,
            columnResizable: true
        }
    });
    grid.setDisplayOptions({
        defaultColumnWidth: 120,
        columnResizable: true
    });
    grid.displayOptions().setDefaultColumnWidth(true);