What Is a Spiral Flute Tap?
A spiral flute tap is a tool used to create threaded holes in materials. Unlike straight-groove taps, which have blades extending in all directions, spiral flute taps feature spiral-shaped blades. This design enhances chip ejection during machining, improving adherence to the hole being tapped.
They are particularly useful for stop holes, where chips might otherwise accumulate at the bottom, causing issues. Spiral flute taps vary in chip evacuation and frictional resistance depending on the manufacturer.
Uses of Spiral Flute Taps
Spiral flute taps are primarily used for machining stop holes in materials such as stainless steel, alloys, carbon steel, and plastics. A stop hole is a blind hole that does not fully penetrate the material, designed to ensure that a bolt stops at a predetermined depth. Due to their ease of use and affordability, spiral flute taps are popular for both industrial applications and DIY projects.
Principle of Spiral Flute Taps
When tapping, a pre-drilled hole is required before creating threads with the tap. The hole must be deeper than the intended depth of the threaded section. While straight groove taps can remove large chips, they often leave small chips at the bottom of the hole. Spiral flute taps address this issue with a helical cutting edge that ejects chips along its groove during rotation. This action discharges material chips outward, clearing the hole. For through-hole tapping, some spiral flute taps are designed to expel chips in the direction of tap travel, known as spiral point taps.