Spiral Tap

Spiral tap is more suitable for machining blind hole threads, and the chips are backwards during machining. Due to the helix angle, the actual cutting front angle of the tap increases as the helix angle increases. According to experience, the helix angle of the processed ferrous metal is selected to be smaller, generally around 30 degrees, to ensure the strength of the helical teeth. When processing non-ferrous metals, the helix angle is chosen to be a little larger, and it can be cut at about 45 degrees.