The Back cycle allows you to perform back bore and countersink NC sequences with a special type of tool, called Back Spotting.

Back drilling is always Blind. You have to specify a start surface and then either select a surface or enter an offset value to define the drilling depth. Unlike other types of drilling, the offset will automatically point in the positive Z direction. See the example for more information on setting up an NC sequence and resulting tool motions for Back drilling and countersinking.