BOTTOMING taps have a lead of two threads and are used when tapping blind holes. Usually preceded by a taper or intermediate tap. Alpha bottoming taps can be identified by their plain shaft, they have no rings on the shaft near the driving square.
Diameter: 18mm
Pitch: 2.5mm
Overall length: 95mm
Shaft Diameter: 14mm
Drive Square: 11mm
Tapping Drill Size: 15.50mm