G81 - standard drilling cycle : G81 X1. Y1. Z-.2 R.1 F3 G99
This cycle can be used for center drilling, drilling, reaming, and rough boring. The cycle travels down at the set feed rate and then rapids out of the hole.
Notice that the depth is somewhat shallow. For drilling deeper holes, another cycle is recommended, like the G73 or G83. Chips can clog in the flutes and break or overheat a drill.