The width of the line in pixels. Also affects the major and minor ticks, but not the grid lines.

Example

<div id="stock-chart"></div>
<script>
$("#stock-chart").kendoStockChart({
    navigator: {
        categoryAxis: {
            line: {
                width: 3
            }
        }
    },
    series: [{
        type: "line",
        field: "value",
        categoryField: "date",
        data: [
            { value: 1, date: new Date(2012, 1, 1) },
            { value: 2, date: new Date(2012, 1, 2) }
        ]
    }]
});
</script>