Currently the RadCartesianChart doesn't support minor grid lines and their implementation is no included in the planning for our next release. However, we have a feature request for minor ticks already logged in our feedback portal
. Keep in mind that, in genera, the grid lines in the chart are snapped to the ticks on the axis.
If you follow the item (the feature request in the portal) you will be notified by email when its status is changed (in progress, completed). Another thing you can keep in mind is that if the item collects certain amount of votes, its priority will increase and it will be more likely for the feature's implementation to be included in our planning.
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