Selecting the correct drill size for a tap is one of the most fundamental skills for a CNC machinist. Guessing or using a "close enough" bit will result in broken taps, scrapped parts, and wasted hours.
Imperial vs. Metric
The manufacturing world uses a mix of Fractional, Wire Gauge (Number), Letter, and Metric drill sizes. Knowing how to cross-reference these systems is vital when reading older blueprints.
Always remember the standard formula for a cut tap: Tap Drill Size = Major Diameter - Pitch.
Don't guess the size.
Access our digital Drill Chart reference specifically designed for CNC machinists to find the exact size you need.
View Drill Chart