
Bits Types & Sizing
Tap Drill Chart: A Practical Guide to Pilot Hole Sizing
5 min
17 articles



A practical, data-driven guide to choosing the correct drill size for a 1/4-20 tap, with material considerations, charts, and best-practice steps from Drill Bits Pro.



Find the correct drill size for a 10-24 tap, with calculation steps and practical tips for reliable tapping. Drill Bits Pro explains material effects, charts, and best practices for clean, precise threads.



Master tap-and-drill charts to pick hole sizes for threads, reducing rework and improving threading quality across metal, plastic, and wood projects for both DIYers and professionals.



Learn how to choose the correct drill size for a 5/16-18 tap across common materials, with step-by-step guidance, a data table, quick-reference stats, and FAQs.
