Tap Drill Size Chart & Calculator

Use this interactive tap drill size chart to find the correct drill bit for any UNC, UNF or metric thread. Search a size or filter by thread type.

Tap Drill Size Chart

Find the correct tap drill for any thread. Search a size (e.g. “1/4-20” or “M6”) or filter by thread type.

Thread sizeTypeTap drillDecimal (in)

Tap drills shown give ~75% thread. For a full drill cross-reference, see our drill bit size chart.

Need to convert those drill sizes? Try our drill bit size converter or the full drill bit size chart.