Tap Drill & Thread Height Chart

1 ThreadMajorThreads perTap DrillTapTap DrillTheoretical %SizeDiameterInch (TPI)RangeDrillDecimalof - - - - - - - - - - - - - - - - - Drill & Thread Height Chart This Chart displays a variety of UN Thread sizes, their likely Tap Drills and the resulting Theoretical Thread Height Percentage. This percentage is thoeretical as holes are often drilled slightly oversized. Typically, tap drills are selected to result in a 60% - 75% Thread Height . There is neglible increased strength in threads with more than 60% Thread Height and larger tap drills are preferred ThreadMajorThreads perTap DrillTapTap DrillTheoretical %SizeDiameterInch (TPI)RangeDrillDecimalof - - - - - - - - - - - - - - - - - - - - - - - - - - perTap DrillTapTap DrillTheoretical %SizeDiameterInch (TPI)

2 RangeDrillDecimalof - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - perTap DrillTapTap DrillTheoretical %SizeDiameterInch (TPI)RangeDrillDecimalof Thread5.