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: 8mm
Pitch: 1.25mm
Overall length: 56mm
Shaft Diameter: 6mm
Drive Square: 4.9mm
Tapping Drill Size: 6.80mm