labelMaxWidth: Number

Sets the maximum width of label after which the it gets wrapped or clipped depending on whether labelWrap is set to true (default) or false.

var  chart =  new  CanvasJS.Chart("container",
{
 .
 .
 axisY:{
	crosshair:{
		enabled: true,
		labelMaxWidth: 20
		.
		.
	}
 },
 .
 . 
});
chart.render();