Taps for CNC
El Cheapo taps should not be used for rigid tapping except in butter. Normal taps for bolt threads come in two flavors for rigid tapping spiral point and spiral flute. Resist the urge to use spiral flute taps for through holes as the body of the tap is weaker and when worn will break easier.
Inspect the cutting edges with a 10x loupe before using. Don’t use any taps that show edge chipping as the torque increases rather fast as the cutting edges wear and chip.
Figure 1: Spiral Point = Through holes, ejects chips downward.
Figure 2: Spiral Flute = Blind holes, pulls chips up and out.