CNC threading tools --carbide tap Product Features: 1. spiral flute tap with a specially designed spiral groove, can be tapped to the very bottom of the blind hole and left no chips in processing hole. 2. The spiral flute tap with a good cut function, so it's easy to cut into the bottom hole. Application: Suitable for cutting curly materials; Suitable for processing blind hole; Suitable for processing the hole that in the inner wall with axial groove.