February 2026 Tip: Basic Thread Dimensions and Tap Drill Sizes
Today, I'm happy to share a new Machinist Tip with you - a three-page PDF of Basic Thread Dimensions and Tap Drill Sizes. The PDF provides information for American National Coarse Threads - formerly A.S.M.E. Regular for sizes 1-12; U.S. Standard for sizes 1/4 inch and larger. Clearly marked D for Major Diameter, E for Pitch Diameter, and K for Minor Diameter. Column headers are as follows: Size of Thread and Threads per Inch Major Diameter D Inches Pitch Diameter E Inches Minor Diameter Internal Threads K Inches Commercial Tap Drill to Produce Approx. 75% Full Thread Decimal Equivalent of Tap Drill Inches Sample of Basic Thread Dimensions and Tap Drill Sizes Thanks again for visiting MachinistKalc.com