Tapped Hole Size Chart. Drilled hole size (mm) = basic major dia. Screw size major diameter minor diameter drill size decimal equivalent;
Drill size for tapping standard metric threads drill size for tapping fine metric threads clearance hole; The data chart below shows the standard metric ‘coarse’ threads and their drill holes sizes were are most commonly used when tapping sheet metal fabrications. Drilled hole size (mm) = basic major dia.