Tap Drill Size Chart: UNC, UNF, Metric & NPT (Printable)
Complete tap drill size chart for UNC, UNF, metric and NPT threads, with clearance holes, a printable quick reference card and formulas to calculate any tap drill.
-
-
3/8-16 Tap Drill Size: Chart, Metric & Clearance Holes
The tap drill for a 3/8-16 UNC thread is a 5/16 in drill (0.3125 in / 7.94 mm). Full chart by thread %, 8.0 mm metric option, clearance holes and 3/8-16 vs M10.
-
10-32 Tap Drill Size: Chart, Metric & Clearance Holes
The tap drill for a 10-32 UNF thread is a #21 drill (0.159 in / 4.04 mm). Full chart by thread %, metric substitutes, clearance holes and 10-32 vs 10-24 vs M5.
-
1/4-20 Tap Drill Size (with Chart)
The tap drill for a 1/4-20 UNC thread is a #7 drill (0.201 in / 5.11 mm). See the full chart by thread percentage, clearance holes, metric and Heli-Coil sizes.
