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: 5/16mm
- Pitch: 18mm
- Overall length: 53mm
- Shaft Diameter: 6mm
- Drive Square: 4.9mm
- Tapping Drill Size: 6.60mm