For High-Production CNC Tapping Without Machine Reversal. Constant Speed Tapping relies on the compact tapping head to provide tap reversal. The machine spindle runs in one direction at the exact programmed speed and reversal occurs within the tapping head instantaneously upon machine retraction. Avoiding the RPM fluctuations,common to machine reversal tapping ensures these benefits: Reduces Cycle Time. Increases Tap Life. Improves Thread Quality. Eliminates Reversal Related Machine Wear & Tear. Reduces Energy Costs.