For Blind drilling, after you specify the starting point you have to also define the end surface, to determine the drilling depth. Use one of:
Surface—Select a surface or create a datum plane to drill up to. If you select a non-planar surface, the depth is defined by the point of intersection of this surface with the hole axis.
Z Depth—Enter an offset value from the starting point (the offset will automatically point towards the workpiece, that is, in the negative Z direction).
See Also